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Screws › Countersunk & Flat-Head Machine Screws

Ss321 Ss321h DIN7991 Hexagon Socket Countersunk Head Cap Screw

Updated 2026-11-04 · Markdown version

Model no. SS321-DIN7991-M8X40

US$1.20300–999 pieces

US$0.961,000–1,999 pieces

US$0.722,000–4,999 pieces

US$0.665,000+ pieces

MOQ 300 pieces · Final price confirmed in your quote

Material: Stainless Steel
Head Style: Hexagonal
Standard: DIN, ANSI, ISO
Grade: Ss321/1.4541
Finish: Passivation
Price for The Size: M12X50
Packing: Small Box
Length: 10-1000mm ; 1/2"-40"

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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	Stainless Steel
Type	Hexagon Head
Model NO.	SS321-DIN7991-M8X40
Connection	Common Bolt
Head Style	Hexagonal
Standard	DIN, ANSI, ISO
Grade	Ss321/1.4541
Application	Building
Finish	Passivation
Price for The Size	M12X50
Marking	ID+Grade
Packing	Small Box
Certificates	En10204-3.1b
How to Make	by Cold Forge
Transport Package	CTN First, Then in Pallet
Specification	M6-64
Origin	Jiangsu, China
HS Code	7318150000
Production Capacity	10 Tons /Month
Hexagon socket	facilitates tightening and untightening with an Allen key. Metric thread: available in metric ISO thread from M3 to M24 to suit different applications.
Length	10-1000mm ; 1/2"-40"
Washers	100 pcs, Nut: 50 pcs ,Bolt and Studs:10 pcs
Category	Countersunk & Flat-Head Machine Screws

Technical parameters

Name	SS321 socket countersink screw
Standard	DIN7991,ISO10642
Size Range	M5-M64 or non-standard as requested
Finish	Bright&Clean
Marking	HT&FST or customization
Material	SS321,1.4541, UNS S32100
Grade	Grade 70,Grade 8T
Certificates	EN10204-3.1B
Non-standards	OEM is available, according to drawing or samples
Samples	Samples available
Package	Bulk in box and then in cartons, then on pallets, or according to customers' requirement.
Payment	T/T,Western Union

GRADE	UNS	W.Nr
SS321	S32100	1.4541

Alloy	%	Ni	Cd	C	Mn	Si	S	Ti	P
321	Min.	9	17					5C
Max.	12	19	0.08	2.0	1.0	0.03	0.7	0.035

Density	7.93 g/cm³
Melting point	1398~1446 ºC

Standard	DIN,ASME,SIO,JIS.BS.NFE,GOST
Size Range	Diameter M5 - M64 ; 1/4"- 2 1/2 Length:10-1000mm ; 1/2"-40"
Material	SS304 ,316,316L ,316LN,316 Lmod,316Ti,317L, 317LN, 321,310S, 904L 254SMO AL-6XN,1.4529
Duplex 2205/2507
Hastelloy C4, C22 , C276 , C2000, B2, B3 , G3 , G30 , Hastelloy X 2.4600 , 2.4602 , 2.4603 , 2.4610 , 2.4617 , 2.4619, 2.4665 , 2.4675 , 2.4819
Inconel600, 601 , 617 , 625 , 690 , 718 , 725 , X750 2.4669 , 2.4668 , 2.4816 , 2.4856 , 2.4851 , 2.4663 , 2.4642
Incoloy800/800H/800HT, Incoloy825 , 90 1, 925 , 926 , 1.4958 , 2.4662 , 1.4529 , 1.4876 , 2.4858 , 1.4959
Monelk500, Monel400; 2.4360 , 2.4375
Titanium Alloy GR2/5/7, 3.7035, 3.7165 , 3.7235
Urea steel 724L ,725LN ; 1.4435 , 1.4466
Alloy20, Alloy28, Alloy31, Alloy 286,Alloy 80A(nimonic 80A) 2.4660 , 1.4563 , 1.4562 , 1.4980 , 2.4952
Product range	Bolt , U bolt , Studs , Threaded Bar , Nut , Washers ,Machining Parts
Marking	According to client's requirements ( OEM )
MOQ	Washers : 100 pcs, Nut: 50 pcs ,Bolt and Studs:10 pcs
Sample policy	sample can be provided in free If we have stock,and the buyer pay the freight cost.
Sample time	7-10 days about
In stock items	SS304/316 Bolt , Nut and washers M6-20
DIN7967 Pal nut M6-20
Titanium Alloy bolt , nut , washers M6-20
Some other sizes may have stock.
One stop purchase	We Will help you to realise one stop purchasing.Our salesman have more than 18 years experience in trading

Description

Ss321 Ss321h DIN7991 Hexagon Socket Countersunk Head Cap Screw is part of our countersunk & flat-head machine screws range (Screws).

Key details

Type: Hexagon Head
Standard: DIN, ANSI, ISO
Material: Stainless Steel
Grade: Ss321/1.4541
Length: 10-1000mm ; 1/2"-40"
Head Style: Hexagonal
Finish: Passivation
Connection: Common Bolt

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 300 pieces at US$0.66 – 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 Ss321 Ss321h DIN7991 Hexagon Socket Countersunk Head Cap Screw?

The listed minimum order is 300 pieces, at US$0.66 – 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 300–999 pieces; US$0.96 for 1,000–1,999 pieces; US$0.72 for 2,000–4,999 pieces; US$0.66 for 5,000+ pieces. Final prices depend on size, material, finish and packing and are confirmed in your quote.

What are the main specifications of Ss321 Ss321h DIN7991 Hexagon Socket Countersunk Head Cap Screw?

Type: Hexagon Head; Standard: DIN, ANSI, ISO; Material: Stainless Steel; Grade: Ss321/1.4541; Length: 10-1000mm ; 1/2"-40"; Head Style: Hexagonal. 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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US$0.66 – 1.20MOQ 300 piecesGet a quote WA