Class 12.9 black countersunk hexagon screws for knife or knives

Mechanical properties

Head markings and mechanical properties

Head marking	Grade, material & condition	Nominal size range [mm]	Proof strength [MPa]	Yield strength (min) [MPa]	Tensile strength (min) [MPa]	Core hardness [Rockwell]
	Class 4.6 Low or medium carbon steel	5–100	225	240	400	B67–95
	Class 4.8 Low or medium carbon steel; fully or partially annealed	1.6–16	310	340	420	B71–95
	Class 5.8 Low or medium carbon steel; cold worked	5–24	380	420	520	B82–95
	Class 8.8 Medium carbon steel; quench and tempered	Under 16 (inc.)	580	640	800
		17–72	600	660	830	C23–34
	Class 8.8 low carbon Low carbon boron steel; quench and tempered
	Class 8.8.3 Atmospheric corrosion resistant steel; quench and tempered
	Class 9.8 Medium carbon steel; quench and tempered	1.6–16	650	720	900	C27–36
	Class 9.8 low carbon Low carbon boron steel; quench and tempered
	Class 10.9 Alloy steel; quench and tempered	5–100	830	940	1040	C33–39
	Class 10.9 low carbon Low carbon boron steel; quench and tempered
	Class 10.9.3 Atmospheric corrosion resistant steel; quench and tempered
	Class 12.9 Alloy steel; quench and tempered	1.6–100	970	1100	1220	C38–44

Details

what we can do

Feedback from customers

Various kinds of fasteners for you reference

 

 

Cardboard package or as requested

 

 

       1 :We can provide samples in 7 days 

       2 :Provide custom made service

       3 :We can help you develop new product

       4 :Quality assurance

        5 :Factory price

 

M-sing Screw Factory with a mature production technology and sophisticated processing techniques, improved detection methods, with the development of strong design capabilities, product quality, the introduction of domestic and international high-precision molds and high-quality raw materials. The main production line with GB, Japan’s JIS, the United States ANSI, the German DIN, BS British standards of bolts, and customers can request all kinds of difficult design and production of standard parts. And through third-party authoritative testing agencies product testing, qualified in the relevant report. Re-header equipment, Roll Machine, tail-cutting, stamping machines, slot milling machines, line cutting, automatic lathes, and other production equipment, some of which more machinery assembling a computer-controlled, automatic detection display, can provide the steady and rapid Zero tolerance of the product, the monthly production capacity of several 10 million.

How to buy from us

        1 : We accept all kinds of payment

        2 : Provide a tiny order if the products needed in our warehouse

        3 : We will reply your email as much as 15 hours