Fortune Hardware Co., LTD

Standard:  ISO 10509:1992, GB/T 16824.2-1997, JIS B1127-1995
Material： SUS301,304,18/8,0Cr18Ni9,X5CrNi1810,X10Cr13,410S21,if you need to use other stainless steel, please let us know.

Heat Treatment: None for normal, If you have special hardness requirement, please let us know.

Surface Hardness：220HV is Normal, 750HV max after Quench with SUS410

Finish：None.

Head：Hex Flange

Tensile strength：700N/mm2
Thread Direction：Normal is right hand/dextrorotation, if you want left hand, please let us know.
Refer to document as below:
                 
Stainless Steel Hex Flange Self Tapping Screws.pdf 

 

  Stainless Steel Hex Flange Self Tapping Screw have a pointed end and widely spaced threads. They're self-starting in thin sheet metal, but in thicker materials a drilled hole is recommended.

 

"Stainless Steel" - With the addition of 12% chromium to iron, stainless steel is formed. The chromium protects the iron against most corrosion or red colored rust; thus the term "stainless steel". The ability of stainless to form a thin layer of protection on its outside surface, called a "passive film", is its most important characteristic in preventing corrosion.

 

"18-8" - 300 series stainless steel having approximately (not exactly) 18% chromium and 8% nickel. The term "18-8" is used interchangeably to characterize fasteners made of 302,302HQ,303,304,384, XM7, and other variables of these grades with close chemical compositions. There is little overall difference in corrosion resistance among the 18-8 types, but slight differences in chemical composition do make certain grades more resistant than others against particular chemicals or atmospheres.

 

Austentic - Refers to 300 series stainless, the most popular of the stainless alloys accounting for 85%-90% of stainless fasteners sold Named for sir Robert Williams Austen, an English metallurgist, austentic stainless is a crystal structure formed by heating steel, chromium, and nickel to a high temperature where it forms the characteristics of 300 series stainless steel.

One advantage the flange hex bolt has over a comparably-sized non-flanged bolt is its ability to displace the clamping force of the fastener over a greater range. On soft, aluminum automobile engine components, the use of a standard hex head bolt could potentially crack and damage the area surrounding the bolt head. With a flange hex bolt, the clamping force is displaced onto a greater area underneath the bolt head, thus saving the aluminum components. Valve covers, intake manifolds and water pumps are some of the aluminum components that often employ a flanged bolt head as a fastener. Other components of the automobile that benefit from the use of the flange hex bolt are the steering box, steering column and transmission.

  

 You can refer to below chart/list of Screw head/Thread ending