b - length of the thread (at least)
l - length of bolt
k - head height
e - the diameter of the circumscribed circle (not less than)
s - size hex head turnkey

Makings:QBH

Steel: steel
Stainless: A2, A4
Plastic: -
Non Ferrous: -
Thread: as DIN 7998

Table according to DIN 571:

Thread			4	5	6	-7	8	10	12	16	20
ds		nominal size max.	4	5	6	7	8	10	12	16	20
ds		min.	3,52	4,52	5,52	6,42	7,42	9,42	11,3	15,3	19,3
da		max.	5	6	7,2	8,2	10,2	12,2	15,2	19,2	24,4
k		nominal size	2,8	3,5	4	5	5,5	7	8	10	13
		max.	3,1	3,88	4,38	5,38	5,88	7,45	8,45	10,45	13,9
		min.	2,5	3,13	3,63	4,63	5,13	6,55	7,55	9,55	12,1
s		nominal size	7	8	10	12	13	17	19	24	30
		max.	7	8	10	12	13	17	19	24	30
		min.	6,64	7,64	9,64	11,57	12,57	16,57	18,48	23,16	29,16
e		min.	7,5	8,63	10,89	13,07	14,2	18,72	20,88	26,17	32,95
l			weight kg/1000pcs
nominal size	min.	max.	weight kg/1000pcs
16	15,1	16,9	1,71	292
20	18,95	21,05	2,01	3,42	5,02
25	23,95	26,05	2,41	4,02	5,82		11,5
30	28,95	31,05	2,81	4,62	6,62		12,9	23,6
35	33,75	36,25	3,11	5,12	7,42		14,2	25,8	36,2
40	38,75	41,25	3,51	5,82	8,22		15,6	28	39,2
45	43,75	46,25			8,94		16,9	30	42,1
50	48,75	51,25			9,64		18,2	32,1	45,4	84,1
55	53,5	56,5			10,5		19,6	34,3	48,6	89,7
60	58,5	61,5			11,2		20,9	36,5	51,8	94,9	165
65	63,5	66,5					22,2	38,5	54,7	99,5	174
70	68,5	71,5					23,6	40,7	57,8	107	182
75	73,5	76,5					25	42,9	61	112	192
80	78,5	81,5					26,5	45,2	64,5	118	201
90	88,25	91,75					29,4	49,9	71	130	220
100	98,25	101,75					32	54	77,1	141	238
110	108,25	111,75							83,4	152	253
120	118,25	121,75							89,5	163	275
130	128	132								175	293
140	138	142								187	317
150	148	152								198	328
160	158	162								209	348
170	168	172									366
180	178	182									385
190	187,7	192,3									404
200	197,7	202,3									421

Process flow

Cold forging

Annealing treatment(if need) ➨ wiredrawing ➨ clod forging ➨ thread rolling ➨make heat treatment(if need) ➨ Finish ➨ Packing

Hot forging

Cutting material ➨ hot forging ➨ turning ➨ shrink diameter(half thread) ➨thread rolling ➨ make heat treatment(if need) ➨ Finish ➨ Packing

Product Grade

Class4.8 Class5.8 Class6.8 Class8.8 Class10.9 Class12.9

NO.	Mechanical or physical property		Property class
			4.6	4.8	5.6	5.8	6.8	8.8		9.8	10.9	12.9/12.9
			4.6	4.8	5.6	5.8	6.8	D≤16mm^a	d＞16mm^b	d≤16mm	10.9	12.9/12.9
1	Tensile strength R_m,Mpa	nom.^c	400		500		600	800		900	1000	1200
1	Tensile strength R_m,Mpa	max.	400	420	500	520	600	800	830	900	1040	1220
2	Lower yield strength R_eL,Mpa	nom.^c	240	——	300	——	——	——	——	——	——	——
2	Lower yield strength R_eL,Mpa	max.	240	——	300	——	——	——	——	——	——	——
3	Stress at 0,2 % nonproportional elongation R_p0.2,Mpa	nom.^c	——	——	——	——	——	640	640	720	900	1080
3	Stress at 0,2 % nonproportional elongation R_p0.2,Mpa	max.	——	——	——	——	——	640	660	720	940	1100
4	Stress at 0,0048 d non-proportional elongation for full-size fasteners R_p^f,Mpa	nom.^c	——	320	——	400	480	——	——	——	——	——
4		max.	——	340^e	——	420^e	480^e	——	——	——	——	——
5	Stress under proof load S_p^f,Mpa	nom.	225	310	280	380	440	580	600	650	830	970
5	Proof S_p,nom/R_{eL min} Or strength S_p,nom/R_p0.2min Or rati S_p,nom/R_{pf min}		0.94	0.91	0.93	0.9	0.92	0.91	0.91	0.9	0.88	0.88
6	Percentage elongation after fracture for machined test pieces,A,%	min.	22	-—	20	——	——	12	12	10	9	8
7	Percentage reduction of area after fracture for machined test pieces,Z,%	min.	——					52		48	48	44
8	Elongation after fracture for full-size fasteners,A_f	min.	——	0.24	——	0.22	0.2	——	——	——	——	——
9	Head soundness		No fracture
10	Vickers hardness, HV, F≥98N	min.	120	130	155	160	190	250	255	290	320	385
10	Vickers hardness, HV, F≥98N	max.	220^g				250	320	335	360	380	435
11	Brinell hardness, HBW ,F=30D²	min.	114	124	147	152	181	238	242	276	304	366
11	Brinell hardness, HBW ,F=30D²	max.	209^g				238	304	318	342	361	414
12	Rockwell hardness,HRB , HRB	min.	67	71	79	82	89
	Rockwell hardness,HRB , HRB	max.	95^g				99.5
	Rockwell hardness, HRC	min.	——					22	23	28	32	39
	Rockwell hardness, HRC	max.	——					32	34	37	39	44
13	Surface hardness HV 0.3	max.	——					h			h,j	h,j
14	Height of non-decarburized thread zone,E,mm	min.	——					1/2H₁			2/3H₁	3/4H₁
14	Depth of complete decarburization in the thread,G,mm	max.	——					0.015
15	Reduction of hardness after retempering,HV	max.	——					20
16	Breaking torque, M_B,N·m	min.	——					in accordance with ISO 898-7
17	Impact strength, K_V^K,I,J	min.	——		27	——		27	27	27	27	m
18	Surface integrity in accordance with		ISO 6157-1ⁿ									ISO 6157-3
a Values do not apply for structural bolting. b For structural bolting d W M12. c Nominal values are specified only for the purpose of the designation system for property classes.See Clause 5. d In cases where the lower yield strength ReL cannot be determined, it is permissible to measure the stress at 0,2 % non-proportional elongation Rp0,2. e For the property classes 4.8, 5.8 and 6.8 the values for Rpf min are under investigation. The present values are given for calculation of the proof stress ratio only. They are not test values. f Proof loads are specified in Tables 5 and 7. g Hardness determined at the end of a fastener shall be 250 HV, 238 HB or 99,5 HRB maximum. h Surface hardness shall not be more than 30 Vickers points above the measured core hardness of the fastener when determination of both surface hardness and core hardness are carried out with HV 0,3. i Any increase in hardness at the surface which indicates that the surface hardness exceeds 390 HV is not acceptable. j Any increase in hardness at the surface which indicates that the surface hardness exceeds 435 HV is not acceptable. k Values are determined at a test temperature of −20 °C, see 9.14. l Applies to d W 16 mm. m Value for KV is under investigation. n Instead of ISO 6157-1, ISO 6157-3 may apply by agreement between the manufacturer and the purchaser.

Materials and Chemical compstition

1008

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu	Al
0.06	0.06	0.33	0.013	0.003	0.01	0	0.01	0.028

1035

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu
0.34	0.13	0.73	0.012	0.002	0.02	0.01	0.02

10B21

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	B
0.2	0.04	0.81	0.017	0.007	0.017	0.0021

1045

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu
0.45	0.23	0.58	0.014	0.006	0.057	0.008	0.016

40CR

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu
0.4	0.21	0.54	0.015	0.008	0.95	0.02	0.02

35CRMO

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu	Mo
0.35	0.22	0.59	0.01	0.003	0.93	0.01	0.01	0.21

42CRMO

CHEMICAL COMPOSI %
C	Si	Mn	P	S	Cr	Ni	Cu	Mo
0.42	0.27	0.92	0.013	0.004	1.01	0.03	0.04	0.2

Finish

PLAIN ZP YZP BLACK HDG DACROMET GEOMET CHROME NICKEL AND SO ON

PACKING

QBH BULK

20-25KG/CTN,36CTNS/PALLET

20-30KG/BAGS,36BAGS/PALLET

ONE TON/BOXES

50KG/ IRON DRUM,12 IRON DRUMS/PALLET

QBH SMALL PACKING

Packing in small boxes according to customer’s requirements

Packing in plastic bag according to customer’s requirements

QBH PALLET TYPE

SOLID WOOD FUMIGATION PALLET

EURO Pallet

THREE SPLINT PALLET

WOODEN BOX

The advantages of QBH

QBH brand sales to the main quality assurance.
Years of export trade management, excellent service, word-of-mouth guarantee.
By working with TUV,escort for quality.
Customization of non-standard parts can be made according to customer's requirements and drawings.
For quality customers,we can provide a certain credit period.

DIN 571 Hex Wood Screws Black CL6.8 Steel Nut Bolts

Steel Nut Bolts

Steel Hex Bolt

Carbon Steel Bolt

High Tensile Stainless Steel Bolts

Carbon Steel Nuts

Stainless Steel Nut

Steel Flat Washer

Spring Steel Washers

Stainless Steel Washer

Fully Threaded Studs

Non Standard Fasteners

Seismic Wedge Anchors

Self Tapping Screw

Electrical Fasteners

Solar Panel Fasteners

Stainless Steel Shackle

DIN 571 Hex Wood Screws Black CL6.8 Steel Nut Bolts

Legend:

Makings:QBH

Table according to DIN 571:

din571 hex wood screws

hex screws din931

din931 hex head bolts