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Screws › Countersunk & Flat-Head Machine Screws

DIN 7991 Hexagon Socket Countersunk Head Cap Screws

Updated 2026-11-04 · Markdown version

Model no. DIN 7991

US$1.201,000–9,999 pieces

US$0.6010,000–99,999 pieces

US$0.36100,000+ pieces

MOQ 1,000 pieces · Final price confirmed in your quote

Material: High Strength Steel
Head Style: Hexagonal
Standard: DIN, ANSI, GB, JIS, GOST
Grade: 8.8
Finish: Hot Galvanizing
Standard for Size: DIN 7991
Standard Name: ISO 10642
Material Grade: 8.8, 10.9, A2-80, A4-80

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Specifications are as listed for this product. Engineering Hardware & Fasteners confirms ratings, mating parts, compatibility, packing and lead time with you before you order.

Specifications

Customization	Available
Material	High Strength Steel
Type	Hexagon Head
Model NO.	DIN 7991
Connection	Common Bolt
Head Style	Hexagonal
Standard	DIN, ANSI, GB, JIS, GOST
Grade	8.8
Application	Machinery, Chemical Industry, Environmental, Building
Finish	Hot Galvanizing
Product Name	Hexagon Socket Countersunk Head Cap Screws
Standard for Size	DIN 7991
Standard Name	ISO 10642
Material Grade	8.8, 10.9, A2-80, A4-80
Diameter Range	M3 - M24
Inch Diameter Range	0# to 1-1/2"
Transport Package	Pallet
Specification	25cm x 25cm x 15cm
Origin	Shanghai
HS Code	7318159090
Production Capacity	10000 Tons Per Year
Package Size	25.00cm * 25.00cm * 15.00cm
Package Gross Weight	25.000kg
Fasteners - Stud bolts - Part 1	Metric thread
Category	Countersunk & Flat-Head Machine Screws

Technical parameters

M10

M12

(M14)

M16

(M18)

M20

(M22)

M24

P	Pitch
α	tol.(+2)
b	L≤125
125
L>200
dk	max=nominal size
min
ds	max=nominal size
min
e	min
k	max
s	Nominal Size
min
max
t	max=nominal size
min

0.5	0.7	0.8	1	1.25	1.5	1.75	2	2	2.5	2.5	2.5	3
90°	90°	90°	90°	90°	90°	90°	90°	90°	90°	90°	60°	60°
12	14	16	18	22	26	30	34	38	42	46	50	54
/	/	/	24	28	32	36	40	44	48	52	56	60
/	/	/	/	/	45	49	53	57	61	65	69	73
6	8	10	12	16	20	24	27	30	33	36	36	39
5.7	7.64	9.64	11.57	15.57	19.48	23.48	26.48	29.48	32.38	35.38	35.38	38.38
3	4	5	6	8	10	12	14	16	18	20	22	24
2.86	3.82	4.82	5.82	7.78	9.78	11.73	13.73	15.73	17.73	19.67	21.67	23.67
2.3	2.87	3.44	4.58	5.72	6.86	9.15	11.43	11.43	13.72	13.72	16	16
1.7	2.3	2.8	3.3	4.4	5.5	6.5	7	7.5	8	8.5	13.1	14
2	2.5	3	4	5	6	8	10	10	12	12	14	14
2.02	2.52	3.02	4.02	5.02	6.02	8.025	10.025	10.025	12.032	12.032	14.032	14.032
2.1	2.6	3.1	4.12	5.14	6.14	8.175	10.175	10.175	12.212	12.212	14.212	14.212
1.2	1.8	2.3	2.5	3.5	4.4	4.6	4.8	5.3	5.5	5.9	8.8	10.3
0.95	1.55	2.05	2.25	3.2	4.1	4.3	4.5	5	5.2	5.6	8.44	9.87

10#

12#

1/4

5/16

d	Nominal Diameter
PP	UNC
UNF
UNEF
ds	max
min
dk	max
min
k	Ref
s	Nominal Size
Nominal Size
t	min
b	min
α	±2°

0.06	0.073	0.086	0.099	0.112	0.125	0.138	0.164	0.19	0.2158	0.25	0.3125
-	64	56	48	40	40	32	32	24	24	20	18
80	72	64	56	48	44	40	36	32	28	28	24
-	-	-	-	-	-	-	-	-	32	32	32
0.06	0.073	0.086	0.099	0.112	0.125	0.138	0.164	0.19	0.2158	0.25	0.3125
0.0568	0.0695	0.0822	0.0949	0.1075	0.1202	0.1329	0.1585	0.184	0.2102	0.2435	0.3053
0.138	0.168	0.197	0.226	0.255	0.281	0.307	0.359	0.411	0.45	0.531	0.656
0.117	0.143	0.168	0.193	0.218	0.24	0.263	0.311	0.359	0.41	0.48	0.6
0.044	0.054	0.064	0.073	0.083	0.09	0.097	0.112	0.127	0.135	0.161	0.198
-	-	-	1/16	1/16	5/64	5/64	3/32	1/8	1/8	5/32	3/16
0.035	0.05	0.05	0.062	0.062	0.078	0.078	0.094	0.125	0.125	0.156	0.188
0.025	0.031	0.038	0.044	0.055	0.061	0.066	0.076	0.087	0.094	0.111	0.135
0.5	0.62	0.62	0.62	0.75	0.75	0.75	0.88	0.88	0.88	1	1.12
82°	82°	82°	82°	82°	82°	82°	82°	82°	82°	82°	82°

3/8

7/16

1/2

5/8

3/4

7/8

1-1/8

1-1/4

1-3/8

1-1/2

d	Nominal Diameter
PP	UNC
UNF
UNEF
ds	max
min
dk	max
min
k	Ref
s	Nominal Size
Nominal Size
t	min
b	min
α	±2°

0.375	0.4375	0.5	0.625	0.75	0.875	1	1.125	1.25	1.375	1.5
16	14	13	11	10	9	8	7	7	6	6
24	20	20	18	16	14	12	12	12	12	12
32	28	28	24	20	20	20	18	18	18	18
0.375	0.4375	0.5	0.625	0.75	0.875	1	1.125	1.25	1.375	1.5
0.3678	0.4294	0.4919	0.6163	0.7406	0.8647	0.9886	1.1086	1.2336	1.3568	1.4818
0.781	0.844	0.938	1.188	1.438	1.688	1.938	2.188	2.438	2.688	2.938
0.72	0.781	0.872	1.112	1.355	1.604	1.841	2.079	2.316	2.553	2.791
0.234	0.234	0.251	0.324	0.396	0.468	0.54	0.611	0.683	0.755	0.827
7/32	1/4	5/16	3/8	1/2	9/16	5/8	3/4	7/8	7/8	1
0.219	0.25	0.312	0.375	0.5	0.562	0.625	0.75	0.875	0.875	1
0.159	0.159	0.172	0.22	0.22	0.248	0.297	0.325	0.358	0.402	0.435
1.25	1.38	1.5	1.75	2	2.25	2.5	2.81	3.12	3.44	3.75
82°	82°	82°	82°	82°	82°	82°	82°	82°	82°	82°

Description

DIN 7991 Hexagon Socket Countersunk Head Cap Screws is part of our countersunk & flat-head machine screws range (Screws).

Key details

Type: Hexagon Head
Standard: DIN, ANSI, GB, JIS, GOST
Material: High Strength Steel
Grade: 8.8
Head Style: Hexagonal
Finish: Hot Galvanizing
Connection: Common Bolt
Application: Machinery, Chemical Industry, Environmental, Building

Available configurations include material, head style, standard, grade and finish. Custom sizes, threads, materials, grades, platings and packaging can be quoted on request.

Ordering through Engineering Hardware & Fasteners

Minimum order is 1,000 pieces at US$0.36 – 1.20 per piece. Send one inquiry with the part number, quantity and destination, and Engineering Hardware & Fasteners confirms size, thread, material, grade, finish, price, lead time and shipping, checks the goods before dispatch and ships them to you.

Frequently asked questions

What is the minimum order quantity (MOQ) for DIN 7991 Hexagon Socket Countersunk Head Cap Screws?

The listed minimum order is 1,000 pieces, at US$0.36 – 1.20 per piece. Smaller trial quantities or samples can be requested in your inquiry; Engineering Hardware & Fasteners confirms what is possible for your size.

How does the price change with quantity?

Volume pricing: US$1.20 for 1,000–9,999 pieces; US$0.60 for 10,000–99,999 pieces; US$0.36 for 100,000+ pieces. Final prices depend on size, material, finish and packing and are confirmed in your quote.

What are the main specifications of DIN 7991 Hexagon Socket Countersunk Head Cap Screws?

Type: Hexagon Head; Standard: DIN, ANSI, GB, JIS, GOST; Material: High Strength Steel; Grade: 8.8; Head Style: Hexagonal; Finish: Hot Galvanizing. The full specification table and any technical parameter tables are listed on this page.

Can this product be customized (OEM)?

Listed configurations include material, head style, standard, grade and finish. Size, thread, length, material and grade, surface finish, head marking, packaging and labels can be quoted to your specification or drawing.

What is the lead time and how is it shipped?

Lead time depends on quantity and customization and is confirmed in your quote. Engineering Hardware & Fasteners checks the goods before dispatch and ships by express, air or sea; mixed orders can be consolidated in one shipment.

Which other countersunk & flat-head machine screws are available?

The Countersunk & Flat-Head Machine Screws category lists 2,424 products in different sizes, materials and finishes: https://engineeringhardware.com/fastener-products/screws/countersunk-flat-head-machine-screws/

How we work

Specified, checked and shipped by Engineering Hardware & Fasteners

Engineering Hardware & Fasteners supplies bolts, screws, nuts, washers, anchors, rivets and fastening hardware to equipment makers, contractors, distributors and maintenance teams. Orders go through one controlled process: size, thread, material, grade and finish confirmed, samples approved, dimensions, thread fit and plating checked before packing, then packed for export — standard or made to drawing.

DIN, ISO, ASTM, ANSI, JIS and GB standard parts
Non-standard parts made to your drawing
Dimensions, thread gauges and plating checked before packing
Export cartons and pallets, consolidated mixed orders
Samples available for approval before mass production

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