GOST 1759.0-87 Bolts, Screws, Studs and Nuts. Specifications

GOST 1759.0-87 (ST SEV 4203-83) applies to bolts, screws, studs and nuts with metric thread per GOST 24705-81, with diameter from 1 to 48 mm.

BOLTS, SCREWS AND STUDS Specifications Bolts, screws and nuts. Specifications	GOST 1759.0-87 (ST SEV 4203-83)

Validity period from 01.01.89 to 01.01.94.

1. Basic parameters and dimensions

1.1. The design, dimensions and surface roughness of bolts, screws, studs and nuts are established in the product standards.

1.2. Tolerances of dimensions, form and location of surfaces — per GOST 1759.1-82.

Basic thread deviations are assigned per GOST 16093-81 depending on the required coating thickness. Thread tolerance fields are specified for uncoated products. After coating, thread requirements shall comply with GOST 16093-81.

1.3. At the customer’s request, bolts, screws and studs may be manufactured with an increased or reduced length of the threaded part.

1.4. By agreement between the manufacturer and the customer, it is permitted to manufacture:

bolts, studs and nuts with left-hand thread;

bolts with a single locking hole in the head.

1.5. Permissible deviations of form from that established in the design standards for bolts, screws, studs and nuts of all product grades shall comply with those specified in mandatory Appendix 5.

2. Technical requirements

2.1. Appearance

2.1.1. The surface of bolts, screws, studs and nuts shall be clean, free from corrosion marks and mechanical damage.

2.1.2. Permissible surface defects of bolts, screws and studs — per GOST 1759.2-82.

2.1.3. Permissible surface defects of nuts — per GOST 1759.3-83.

2.2. Mechanical properties and materials

2.2.1. Mechanical properties of bolts, screws (except set screws) and studs made of carbon unalloyed and alloyed steels — per GOST 1759.4-87.

2.2.2. Mechanical properties of set screws and similar fasteners not subjected to tensile load, made of carbon unalloyed and alloyed steels — per GOST 25556-82.

2.2.3. Mechanical properties of nuts made of carbon unalloyed and alloyed steels — per GOST 1759.5-87.

2.2.4. Mechanical properties of bolts, screws, studs and nuts made of corrosion-resistant, heat-resistant, high-temperature and heat-stable steels, as well as recommended steel grades — per tables 1 and 2.

2.2.5. Mechanical properties of bolts, screws, studs and nuts made of non-ferrous alloys, as well as recommended alloy grades — per tables 3 and 4.

2.2.6. Bolts, screws, studs and nuts may be manufactured from materials and alloys not specified in tables 1–4. In this case, their mechanical properties shall not be lower than those specified for the corresponding groups.

2.2.7. At the customer’s request, fasteners made of brass by cold heading shall be subjected to heat treatment to relieve internal stresses.

2.3. Coatings

2.3.1. Bolts, screws, studs and nuts shall be manufactured with one of the coating types per table 5, or without coating. Other types of coatings may be used — per GOST 9.303-84.

2.3.2. Selection of coating thickness — per GOST 9.303-84.

2.3.3. Technical requirements for coatings — per GOST 9.301-86.

Table 1

Mechanical properties of bolts, screws and studs made of corrosion-resistant, heat-resistant, high-temperature and heat-stable steels at normal temperature

Group designation	Tensile strength σv, N/mm²	Yield strength, σt (σ0.2) N/mm²	Elongation d₅, %	Impact strength KCU, J/cm²	Proof load stress σp, N/mm²	Steel
						Grade	Standard designation
	Min
21	510	195	35	Not regulated	175	12Kh18N10T 12Kh18N9T 10Kh17N13M2T 10Kh17N13M3T 06KhN28MDT	GOST 5632-72
22	590	345	20	60	310	12Kh13 08Kh21N6M2T
23	690	540	12	60	485	20Kh13 14Kh17N2
24	880	540	8	30	485	10Kh11N23T3MR
25		735	10	30	660	13Kh11N2V2MF
						25Kh1MF; 25Kh2M1F 20Kh1M1F1TR	GOST 20072-74
26	1080	835	10	50	750	07Kh16N6	GOST 5632-72

Table 2

Mechanical properties of nuts made of corrosion-resistant, heat-resistant, high-temperature and heat-stable steels at normal temperature

Group designation	Stresses under proof load sF, N/mm², not less than	Steel
		Grade	Standard designation
21	510	12Kh181-10T, 12Kh18N9T 10Kh17N13M2T 10X17I-113M3T 06 KhN 28 MDT	GOST 5632-72
22	590	12Kh13 08Kh21N6M2T
23	690	20Kh13, 14Kh17N2
24 25	880	10Kh11N23T3MR 13Kh11N2V2MF
		25Kh1MF, 25Kh2M1F 20Kh1M1F1TR	GOST 20072-74
26	1080	07Kh16N6	GOST 5632-72

Table 3

Mechanical properties of bolts, screws and studs made of non-ferrous alloys at normal temperature

Group designation	Tensile strength σv, N/mm²	Yield strength, σt (σ0.2) N/mm²	Elongation d₅, %	Brinell hardness HB	Material or alloy grade	Standard designation
	Min
31	260	120	15	Not regulated	AMg5P AMg5	GOST 4784-74
32	310	Not regulated	12	75	Brass L63, Brass LS59-1	GOST 15527-70 GOST 12920-67
33					Brass LS59-1, non-magnetic Brass L63 non-magnetic
34	490			Not regulated	Bronze Br. AMi9-2	GOST 18175-78
35	370	195	10		D1, D1P, D16, D16P	GOST 4784-74

Table 4

Mechanical properties of nuts made of non-ferrous alloys at normal temperature

Group designation	Stresses under proof load sF, N/mm², not less than	Material or alloy grade	Standard designation
31	260	AMg5P, AMg5	GOST -178-1-74
32	310	Brass LS59-1, L63	GOST 15527-70,
33		Brass L63 non-magnetic Brass LS59-1 non-magnetic	GOST 12920-67
34	490	Bronze Br, AMts 9-2	GOST 18175-78
35	370	D1, D1P, D16, D16P	GOST 4784-74

Table 5

Coating type	Coating designation
	per GOST 9.306-85	numeric
Zinc, chromated	Ts.Kh	01
Cadmium, chromated	Kd. Kh	02
Multilayer: copper-nickel	M.N	03
Multilayer: copper-nickel-chromium	M. N. Kh. b	04
Oxide, oil-impregnated	Chem. oxide, oil-impr.	05
Phosphate, oil-impregnated	Chem. phosphate, oil-impr.	06
Tin	O	07
Copper	M	08
Zinc	Ts	09
Oxide, chromate-filled	Chem. oxide, chromate-filled	10
Oxide from acid solutions	Chem. passivated	11
Silver	Sr	12
Nickel	H	13

2.4. Marking

2.4.1. General marking rules

2.4.1.1. Hex head bolts, screws with a cylindrical head and hex socket, studs, and hexagon nuts are marked with the property class symbol (or material group symbol) and the manufacturer’s trademark; parts with left-hand thread are additionally marked with a left-hand thread symbol.

The following are subject to mandatory marking:

hex head bolts of property classes 4.6, 5.6, 6.6, 8.8, 9.8, 10.9, 12.9;

screws with a cylindrical head and hex socket, and studs, of property classes 8.8, 9.8, 10.9, 12.9;

nuts of property classes 05, 8, 9, 10, 12.

2.4.1.2. Items not listed in 2.4.1.1, of unspecified property classes, as well as those manufactured by machining, are marked by agreement between the manufacturer and the purchaser.

2.4.1.3. Marking symbols may be raised or recessed.

2.4.1.4. When marking property classes, the dot separating the first and second numbers of the property class symbol may be omitted.

When low-carbon martensitic steels are used for property class 10.9 items, the property class symbol must be underlined: 10.9 or 109.

2.4.1.5. The dimensions of marking symbols are set by the manufacturer.

2.4.2. Marking of hex head bolts and screws with a cylindrical head and hex socket

2.4.2.1. Marking applies to bolts and screws with thread diameter d ≥ 6 mm.

2.4.2.2. Marking symbols are applied to the end or side surface of the head (Fig. 1). Symbols on the side surface must be recessed.

Fig. 1

2.4.2.3. When marking with raised symbols, an increase in the maximum head height is permitted by:

0.1 mm — for items with thread diameter d ≤ 8 mm;

0.2 mm — for 8 mm ≤ d ≤ 12 mm;

0.3 mm — for d > 12 mm.

2.4.3. Marking of studs

2.4.3.1. Marking applies to studs with thread diameter d ≥ 12 mm. Studs with thread diameter d ≥ 8 mm may be marked using substitute symbols:

○ — for property class 8.8;

• — 9.8;

□ — 10.9;

∆ — 12.9.

2.4.3.2. Marking symbols are applied to the end face of the nut end of the stud.

2.4.4. Marking of hexagon nuts

2.4.4.1. Marking applies to nuts with thread diameter d ≥ 5 mm.

2.4.4.2. Marking symbols are applied to one of the end faces. In technically justified cases, symbols may be applied to the side surfaces of nuts (Fig. 2). Symbols must be recessed.

Fig. 2

2.4.4.3. Dial-type marking of nuts is permitted (Fig. 3) — on the chamfers with raised or recessed symbols, or on the end face with recessed symbols.

2.4.5. Marking of bolts, studs and nuts with left-hand thread

2.4.5.1. The left-hand thread symbol is an arrow indicating the screwing-in direction of the bolt and stud and the tightening direction of the nut.

Property class	8	9	10	12
Dial-type marking of nuts

Fig. 3

2.4.5.2. The left-hand thread symbol is applied to the end surface of the bolt head, to one of the end surfaces of the nut (Fig. 4a), and to the end face of the nut end of the stud. In technically justified cases, it may be applied to the side surfaces of the nut and bolt heads (Fig. 4b) — in this case the symbols must be recessed.

2.4.5.3. The left-hand thread symbol for bolts and nuts may be replaced by notches on the edges of the hexagons (Fig. 4c).

Fig. 4

3. Acceptance

3.1. Acceptance rules — per GOST 17769-83.

3.2. Each batch of fasteners must be accompanied by a quality document indicating:

the name or trademark of the manufacturer;

the item’s designation;

the list and results of the tests performed;

the net weight of the batch;

means of temporary corrosion protection and the protection period.

Note. The quality document may be placed inside the packaging or container, provided it is preserved during transportation.

Until 01.01.92, the following tests are mandatory:

per GOST 1759.4-87, for property classes 8.8–12.9 — determination of tensile strength and impact toughness; for property classes 4.8, 5.8, 6.8 — testing of the head-to-shank joint strength;

per GOST 1759.5-87, for property classes 8–12 — proof load testing.

Other tests are performed at the purchaser’s request.

4. Test methods

4.1. Visual inspection is performed without magnifying instruments. In disputed cases, a magnifying glass with 2.5–3× magnification may be used.

4.2. Inspection of surface defects of bolts, screws and studs — per GOST 1759.2-82.

4.3. Inspection of surface defects of nuts — per GOST 1759.3-83.

4.4. Dimensional inspection — per GOST 1759.1-82.

4.5. The chamfering of the corners of the square neck is checked in a test die with a square hole per row 1 of GOST 16030-70. A flat washer with a hole diameter larger than the circumscribed circle diameter of the neck, and a thickness of 0.5 of the neck height, is placed under the bolt head. Rotation of the neck in the hole of the test bushing or gauge is not permitted.

4.6. Surface roughness is checked by comparison with roughness samples per GOST 9378-75. Inspection using measuring instruments is also permitted. The surface roughness of items made by cold forming, and the roughness of the shank end face (except for set screws), is not inspected.

4.7. The thread roughness of bolts, screws and studs is checked on the side surfaces of the profile. The roughness of rolled threads and the thread roughness of nuts is not inspected and must be ensured by the manufacturing process and tooling.

4.8. Methods for checking the quality and thickness of coatings — per GOST 9.302-88.

4.9. Test methods and programs for bolts, screws and studs made of carbon unalloyed and alloyed steels — per GOST 1759.4-87.

4.10. Tests of bolts, screws and studs made of corrosion-resistant, heat-resistant, heat-resisting and heat-tolerant steels, as well as non-ferrous alloys, are performed at the purchaser’s request in accordance with Table 6 using the procedure of GOST 1759.4-87. Breaking loads are given in Appendix 2, proof loads in Appendix 4. Other tests are performed by agreement between the manufacturer and the purchaser.

4.11. Test methods for nuts made of carbon unalloyed and alloyed steels — per GOST 1759.5-87.

4.12. Proof load tests of nuts made of corrosion-resistant, heat-resistant, heat-resisting and heat-tolerant steels, as well as non-ferrous alloys, are performed at the purchaser’s request using the procedure of GOST 1759.5-87. Proof loads are given in Appendix 3.

4.13. When bolts, screws and studs are manufactured by machining without subsequent heat treatment, mechanical property tests may be performed on the base metal or on specimens made from it.

Table 6

Mechanical properties	Test type	Material groups
		21	22, 23, 24, 25, 26	31, 35	34	32, 33
Tensile strength	Tensile test	´ 0	´ 0	´ 0	´ 0	´ 0
Yield strength	Tensile test	´	´	´	-	-
Elongation	Tensile test	´	´	´	´	´
Brinell hardness	Hardness measurement					´ 0
Impact toughness	Impact toughness test		´

0 — for bolts, screws and studs with thread d ≤ M5 or length < 3d;

× — for bolts, screws and studs with thread d > M5 and length ≥ 3d.

5. Transportation and storage

Temporary corrosion protection of products, packaging, container marking, transportation and storage — in accordance with GOST 18160-72.

Designation example:

Screw — per GOST 17473-80, product grade A, design 2, with nominal thread diameter d=12 mm, fine thread pitch, thread tolerance class 6e, length l=60, property class 5.8, made of killed steel with a zinc coating 9 µm thick, chromated:

Screw A2M12×1.25-6e×60.58.C.019 GOST 17473-80

Nut — per GOST 5916-70, design 2, with nominal thread diameter d=12 mm, fine thread pitch, left-hand thread, tolerance class 6H, property class 05, made of steel grade 40Kh, with a zinc coating 6 µm thick, chromated:

Nut 2M12×1.25-LH-6H.05.40Kh.016 GOST 5916-70

Notes:

1. The designation does not indicate: design 1, coarse thread pitch, right-hand thread, absence of coating, as well as parameters uniquely defined by product standards; product grade B, if the standard for a specific product provides for 2 product grades (A and B).

2. If a coating not covered by this standard is used, its designation is specified in accordance with GOST 9.306-85.

Appendix 2 (mandatory)

Table 7

Minimum breaking loads for bolts, screws and studs with coarse thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Minimum breaking load, N, for designations of groups
			21	22	23	24; 25	26	31	32; 33	34	35
4	0.7	8.78	4470	5170	6050	7720	9470	2280	2720	4290	3240
5	0.8	14.2	7240	8380	9800	12500	15300	3690	4400	6960	5250
6	1	20.1	10300	11900	13900	17700	2-1700	5230	6230	9850	7440
7	1	28.9	14700	17000	19900	25300	31100	7500	8900	14100	10660
8	1.25	36.6	18700	21600	25300	32200	39500	9520	11300	17900	13500
10	1.5	58.0	30100	34800	40700	51900	63700	15100	18000	28400	21500
12	1.75	84.3	42900	49700	58100	74100	90900	21900	26100	41300	31200
14	2	115	58700	67900	79400	101000	124000	29900	35700	56400	42600
16	2	157	80100	92600	108000	138000	170000	40800	48700	76900	58100
18	2.5	192	97900	113000	132000	169000	207000	49900	52500	94100	71000
20	2.5	245	125000	145000	169000	216000	265000	63700	76000	120000	00700
22	2.5	303	155000	179000	209000	267000	327000	78800	93900	148000	112000
24	3	353	176000	208000	243000	310000	380000	91500	100000	172000	130000
27	3	459	234000	271000	317000	404000	496000	119000	142000	225000	170000
30	3.5	561	286000	330000	386000	493000	605000	146000	174000	274000	207000
33	3.5	694	353000	410000	478000	610000	748000	180000	215000	340000	250000
36	4	817	416000	480000	563000	718000	881000	212000	253000	400000	302000
39	4	976	497000	575000	673000	860000	1053000	253500	302000	478000	361000
42	4.5	1120	571000	661000	773000	986000	1210000	291000	347000	549000	414000
45	4.5	1306	666000	770000	901000	1150000	1410000	339600	405000	640000	483000
48	5	1472	751000	868000	1020000	1300000	1590000	383000	456000	721000	545000

Table 8

Minimum breaking loads for bolts, screws and studs with fine thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Minimum breaking load, N, for designations of groups
			21	22	23	24; 25	26	31	32; 33	34	35
8	1	39.2	19900	23100	27000	34400	42200	10200	12100	19200	14500
10	1.25	61.2	31200	36100	42200	53900	66100	15900	19000	30000	22600
12	1.25	92.1	46900	54300	63500	81000	99400	23900	28500	45100	34000
14	1.5	125	63200	73200	85600	109000	134000	32200	38400	60800	45900
16	1.5	167	85200	98500	115000	147000	180000	43400	51800	81800	61800
18	1.5	216	110000	127000	149000	190000	233000	56200	67000	106000	79900
20	1.5	272	136000	160000	187000	238000	293000	70500	84000	133000	10000
22	1.5	333	170000	196000	230000	293000	360000	86600	103000	163000	123000
24	2	384	196000	227000	265000	338000	415000	998000	119000	188000	142000
27	2	496	252000	292000	342000	436000	535000	129000	153000	243000	183000
30	2	621	317000	366000	428000	546000	671000	161000	193000	304000	230000
33	2	761	388000	449000	525000	670000	822000	198000	236000	373000	282000
36	3	865	441000	510000	596000	760000	933000	225000	268000	423000	320000
39	3	1030	525000	608000	711000	906000	1112000	268000	319000	505000	381000
42	3	1205	615000	711000	830000	1060000	1300000	313000	374000	590000	446000
45	3	1400	714000	826000	966000	1232000	1512000	364000	434000	686000	518000
48	3	1603	818000	946000	1110000	1411000	1731000	417000	497000	785000	593000

Appendix 3 (mandatory)

Table 9

Proof load for nuts with height m ≥ 0.8d with coarse thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Proof load, N, for designations of groups
			21	22	23	24; 25	26	31	32; 33	34	35
1.6	0.35	1.27	650	750	880	1120	1370	330	390	620	470
2	0.4	2.07	1060	1220	1430	1820	2240	540	640	1010	770
2.5	0.45	3.39	1730	2000	2340	2980	3660	880	1050	1660	1250
3	0.5	5.03	2570	2970	3470	4430	5430	1310	1560	2460	1860
3.5	0.6	6.78	3450	3990	4670	5960	7310	1760	2100	3320	2500
4	0.7	8.78	4470	5170	6060	7720	9470	5280	2720	4300	3240
5	0.8	14.2	7240	8380	9800	12500	15300	3690	4400	6960	5250
6	1	20.1	10300	11900	13900	17700	21700	5230	6230	9850	7440
7	1	28.9	14700	17000	19900	25300	31100	7490	8930	14109	10700
8	1.25	36.6	18700	21600	25300	32200	39500	9520	11300	17900	13500
10	1.5	58.0	29600	34200	40000	51000	62600	15100	18000	28400	21500
12	1.75	84.3	49200	49700	58100	74100	90900	21900	26100	41300	31200
14	3	115	587000	67900	79400	101000	124000	29900	35700	56400	42600
16	2	157	80100	92600	108000	138000	170000	40800	48700	76900	58100
18	2.5	192	97900	113000	132000	169000	207000	49900	59500	94100	71000
20	2.5	245	125000	145000	169000	216000	265000	63700	76000	120000	90700
22	2.5	303	155000	179000	209000	267000	327000	78800	93900	148000	112000
24	3	353	180000	208000	243000	310000	380000	91500	109000	172000	130000
27	3	459	234000	271000	317000	404000	496000	119000	112000	225000	170000
30	3.5	561	286000	330000	386000	493000	605000	146000	174000	274000	207000
33	3.5	694	353000	409000	478000	610000	748000	180000	215000	340000	256000
36	4	817	416000	480000	563000	718000	881000	212000	253000	400000	302000
39	4	976	497000	575000	673000	858000	1053000	254000	302000	478000	361000
42	4.5	1120	571000	661000	773000	986000	1210000	291000	347000	549000	414000
45	4.5	1305	666000	770000	900000	148000	1409000	339000	405000	640000	483000
48	5	1472	751000	868000	1016000	1296000	1590000	383000	456000	721000	545000

Table 10

Proof loads for nuts with height m ≤ 0.8d with fine thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Proof load, N, for designations of groups
			21	22	23	24; 25	26	31	32; 33	34	35
8	1	39.2	19900	23100	27000	34400	42200	10200	12100	19200	14500
10	1	64.5	32900	38100	44500	56800	69700	16800	20000	31600	23900
10	1.25	61.2	31200	36100	42200	53900	66100	15900	19000	30000	22600
12	1.25	92.1	46900	54300	63500	81000	99400	23900	28500	45100	34000
12	1.5	88.1	44900	52000	60800	77500	95100	22900	27300	43200	32600
11	1.5	125	63200	73200	85600	109000	134000	32200	38400	60800	45900
16	1.5	167	85200	98500	115000	147000	18000	43400	51800	81800	61800
18	1.5	216	110000	127000	149000	190000	233000	56200	67000	106000	79900
18	2	204	104000	120000	141000	180000	220000	53000	63200	100000	75500
20	1.5	272	138000	100000	187000	238000	293000	70500	84000	133000	100000
20	2	258	132000	152000	178000	227000	279000	67100	80000	126000	95500
22	1.5	333	170000	196000	230000	293000	360000	86600	103000	163000	123000
22	2	318	162000	188000	219000	280000	343000	82700	98600	156000	118000
24	1.5	401	205000	237000	277000	353000	433000	104000	124000	196000	148000
24	2	384	196000	327000	265000	338000	415000	99800	119000	188000	142000
27	2	496	252000	292000	342000	436000	535000	129000	153000	243000	183000
30	2	621	317000	366000	428000	546000	671000	161000	193000	304000	230000
33	2	761	388000	448000	524000	669000	821000	198000	236000	372000	281000
36	3	865	441000	510000	596000	760000	933000	225000	268000	423000	320000
39	3	1030	524000	607000	709000	905000	1105000	266000	317000	501000	379000
42	3	1205	615000	711000	831000	1060000	1301000	313000	374000	590000	446000
45	3	1397	712000	824000	964000	1229000	1509000	363000	433000	685000	517000
48	3	1603	818000	946000	1122000	1411000	1731000	417000	497000	785000	593000

Appendix 4 (mandatory)

Table 11

Proof loads for bolts, screws and studs with coarse thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Proof load, N, for designations of groups
			21	22	23; 24	25	26
4	0.70	8.78	1540	2720	4260	5790	6590
5	0.80	14.20	2490	4400	6890	9370	10700
6	1.00	20.10	3520	6230	9760	13300	16100
7	1.00	28.90	5068	8960	14000	19100	21700
8	1.25	36.60	6410	11300	17800	24200	27500
10	1.50	58.00	10200	18000	28100	38300	43500
12	1.75	84.30	14800	26100	40900	55600	63200
14	2.00	115.00	20100	35700	55800	75900	86300
16	2.00	157.00	27500	48700	76100	104000	118000
18	2.50	192.00	33600	59500	93100	127000	144000
20	2.50	245.00	42900	76000	119000	162000	184000
22	2.50	303.00	53000	93900	147000	200000	227000
24	3.00	353.00	61800	109000	171000	233000	265000
27	3.00	459.00	80300	142000	223000	303000	344000
30	3.50	561.00	98000	174000	272000	370000	421000
33	3.50	694.00	121000	215000	337000	458000	521000
35	4.00	817.00	143000	253000	396000	539000	613000
39	4.00	976.00	171000	303000	473000	644000	732000
42	4.50	1120.00	196000	347000	543000	739000	840000
45	4.50	1306.00	229000	405000	633000	862000	980000
48	5.00	1472.00	258000	456000	714000	972000	1104000

Table 12

Proof loads for bolts, screws and studs with fine thread pitch

Nominal thread diameter, d, mm	Thread pitch P, mm	Nominal cross-sectional area As, mm²	Proof load, N, for designations of groups
			21	22	23; 24	25	26
8	1.00	39.2	6840	12200	19000	25800	29400
10	1.25	61.2	10700	19000	29700	40400	45900
12	1.25	92.1	16100	28600	44700	60800	69000
14	1.50	125.0	21900	38800	60600	82500	93800
16	1.50	167.0	29200	51800	81000	110000	125000
18	1.50	216.0	37800	67000	105000	143000	162000
20	1.50	272.0	47600	84000	132000	179000	204000
22	1.50	333.0	58300	103000	162000	220000	250000
24	2.00	384.0	67200	119000	186000	253000	288000
27	2.00	496.0	86800	154000	241000	327000	372000
30	2.00	621.0	109000	193000	301000	410000	466000
33	2.00	761.0	133000	236000	369000	502000	571000
36	3.00	865.0	151000	268000	419000	571000	649000
39	3.00	1030.0	180000	919000	500000	680000	773000
42	3.00	1205.0	211000	374000	584000	795000	904000
45	3.00	1400.0	245000	434000	679000	924000	1050000
48	3.00	1603.0	281000	497000	777000	1058000	1202000

Appendix 5 (mandatory)

1. Chamfer on the bearing surface of bolts — at an angle of not more than 15° (Fig. 5).

Fig. 5

2. Blunting of the hexagon or square edges toward the bearing surface or end face of the bolt head and toward the bearing surface of the nut — not more than 0.25 of the height of the bolt or nut head (Fig. 6).

Fig. 6

3. Rounding of the hexagon or square edges must not cause the circumscribed circle diameter to exceed the minimum limit dimension.

4. Rounding of the head rim on bolts and screws with countersunk and raised countersunk heads, and of the edges on bolts and screws with round (button) and cylinder heads, must not cause the head diameter to exceed the minimum limit dimension.

5. An underfill in the form of a flat truncation at the top of round (button), spherical and raised countersunk heads is permitted, provided the diameter of the truncated flat does not exceed 30% of the nominal head diameter for product grade A and 40% for product grades B and C. The underfill must not cause the head height to exceed the minimum limit dimension.

6. The taper of the head generator of not more than 5° and the sphere on the top face of the head must not cause the height of the cylinder head to exceed the maximum limit dimension (Fig. 7).

Fig. 7

7. The reduction in the minimum head diameter in the direction of the slot must not exceed:

0.3 mm — for screws with a thread diameter up to 2 mm;

0.6 mm — from over 2 mm to 6 mm;

0.8 mm — over 6 mm.

8. The reduction in the minimum diameter of round (button) and countersunk heads in the direction of the lug or edges of the square neck must not exceed:

0.6 mm — for bolts with a head diameter up to 30 mm;

0.8 mm — over 30 mm.

9. Blunting of the corners of the square neck must not cause the bolt to rotate in the control die.

10. The thickening of the shank diameter under the head of bolts and screws for products of product grades A and B must not exceed:

0.05 mm over a length of 5 mm at a thread diameter up to 16 mm;

0.1 mm over a length of 8 mm at a thread diameter from 16 to 27 mm;

0.2 mm over a length of 10 mm at a thread diameter over 27 mm.

For products of product grade C — not more than the limit deviations of tolerance field +JT14 over a length of two nominal thread diameters.

11. An oblique cut of the shank with a width not exceeding:

one thread pitch — for product grades A and B;

two thread pitches — for product grade C.

Fig. 8

12. Countersinking of cotter pin holes — with a diameter not exceeding 1.5 times the hole diameter.

13. The slope of the slot walls (angle α — Fig. 9) not more than:

3° — for product grade A;

5° — for product grades B and C.

Fig. 9

14. A center hole on the end face of the head and shank is permitted.

15. The absence of an end chamfer is permitted on products of product grade C with rolled thread and on the shanks of screws of product grades A and B with rolled thread. By agreement between the purchaser and the manufacturer, the absence of an end chamfer is permitted on the shanks of bolts and studs of product grades A and B with rolled thread.

16. Rounding of the top face of the head instead of a chamfer is permitted on bolts with a recess in the head.

17. A concavity of the slot bottom along its length, with a curvature corresponding to the radius of a standard slotting or slitting mill cutter, is permitted, as is a convexity with a radius of not less than 90 mm for screws with a thread diameter up to 12 mm and not less than 150 mm for screws with a thread diameter over 12 mm.

18. The presence of a crater in the nut thread turns (when the thread is produced by rolling) must not cause the thread dimensions to exceed the limit deviations.

Informational data

Developed and submitted by the Ministry of Ferrous Metallurgy of the USSR.

Approved and put into effect by Decree of the USSR State Committee for Standards dated 30.12.87 No. 5111.

Review date — 1993.

The standard fully complies with ST SEV 4203-83.

Supersedes GOST 1759-70 (in terms of technical requirements and marking of fasteners).

Referenced normative-technical documents:

Designation of the referenced regulatory document	Clause, sub-clause requirement
GOST 9.301-86	2.3.3
GOST 9.302-79	4.8
GOST 9.303-84	2.3.1 , 2.3.2
GOST 9.306-85	2.3.1
GOST 1759.1-83	4.4
GOST 1759.2-82	2.1.2 , 4.2
GOST 1759.3-83	2.1.3 , 4.3
GOST 1759.4-87	2.2.1 , 4.9, 4.10
GOST 1759.5-87	2.2.3 , 4.11, 4.12
GOST 4781-74	2.2.5
GOST 5632-72	2.2.4
GOST 9378-75	4.6
GOST 12920-67	2.2.5
GOST 15527-70	2.2.5
GOST 16030-70	4.5
GOST 17769-83	3.1
GOST 18160-72	5
GOST 18175-78	2.2.5
GOST 20072-72	2.2.4
GOST 24705-81	Introductory part
GOST 25556-82	2.2.2