Grade 10.9 bolt

[lloydwalker]

I have a small screw machine shop where I make spacers and bolts from 12l14 steel. I have a customer who wants a 10mm bolt made which must be equivalant to a grade 10.9

What material should I use and what process needs to be done after it is made to bring it to a grade 10.9?

 

[Yallapragada1022]

Go to the following sites. They don't really specify the steel grade. All it says is alloy steel (quenched & tempered).

http://www.engineersedge.com/hex_bolt_identification.htm

http://www.americanfastener.com/technical/grade_markings_steel.asp

Hope this helps.

 

[CoryPad]

What must be equivalent? Composition, proof/yield/tensile strength, elongation, impact energy? If it must meet property class 10.9 requirements according to ISO 898-1, then you should obtain the specification to learn what is necessary.

If you need a screw machining material with ultimate tensile strength near 1000 MPa, then Stressproof and "e.t.d." 150 from Niagra are popular:

http://www.niagaralasalle.com/products/index.html

Just be aware that these don't necessarily meet all the requirements of ISO 898-1.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[TVP]

As CoryPad mentioned, free machining grades do not meet all of the requirements of ISO 898-1 Property Class 10.9. The chemical composition is essentially restricted such that cold-heading grades of alloy steels (4037, 4140, 1541, etc.) are the only allowable materials. SAE J1199 is even more restrictive, as it specifies that property class 4.8, 5.8, 8.8, 9.8, and 10.9 bolts and screws in sizes up to M20 inclusive be cold headed. You should have an honest conversation with your customer to decide whether or not machined parts should be used. Fatigue performance and impact strength will be better with a cold headed part, so if this is a requirement for the application, beware.

 

[limct]

http://www.bossard.com/techinfo/en/index.html

This website will surely help. Go to Section "s".

By the way, for 10.9 class fastener, black oxide finishing is recommended, zinc plating will promote the risk of hydrogen embrittlement.

Good luck to you.

Best regards,
ct

 

[Kenneth]

Does "equivalency" require grademarking (marking with "10.9") or representing/selling the parts as meeting Grade 10.9? If so, manufacturing bolts to anything less than the full requirments of the ISO standard is a SEROIUS crime punishable by both civil and criminal penalties per the Fastener Quality Act (

http://ts.nist.gov/WeightsAndMeasures/fqa.cfm).

Tread carefully and follow the advice of the other posters. Get and read a copy of the referenced ISO standard to know what you're getting into...

 

[dbooker630]

I prefer 10.9 fasteners from 4140 steel. Depending upon the diameter of the fastener, 4037 will work as well. With either of these two the heat treat concerns are minimized.
1541 manganese grade is allowed up to M12 size.

Where material costs are an issue, Boron steels like 10B30 are increasing in usage (Europe) but be careful of the hardenability and heat treat practice. This material requires customer approval.

 

[Kenneth]

What's the boron content of 10B30?

I note that ISO 898-1 limits the boron content of material used to fabricate property class 10.9 fasteners to .003% (.005% provided that "non-effective boron is controlled by addition of titanium and/or aluminum").

 

[CoryPad]

Boron mass concentration of 0.003 % maximum is used for ISO 898-1, ASTM A 320/320M, ASTM F 2282, SAE J403 and SAE J1199 . Boron mass concentration of 0.005% maximum is allowed by ASTM F 568M and SAE J429.

Regards,

Cory

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