Need to make bolts--What type of steel?

[gasengin]

I am needing at make some special bolts for a project. I would like them to be at least equivalent to grade 5 bolts. What type of steel would give me that strength and still be able cut nice smooth threads in it?

 

[gradient]

Could you start with a bigger version of an existing bolt and machine it down to what you need? Might save some time.

 

[silverhawk]

It actually depends on the bolt. Different bolts of different hardness for different applications. Are you needing a grade 2/5/8? (Lots of other options here, just need to know what you want. )

joe

 

[MrWhoopee]

Stressproof for medium strength or ETD-150 for high strength. Both offer excellent machinability and are available on eBay.

 

[gasengin]

Could you start with a bigger version of an existing bolt and machine it down to what you need? Might save some time.

Needs both a special head and odd thread pitch (1/2-12). It is for an antique engine before the 13 thread standard.

 

[Mitch Alsup]

Stressproof for medium strength or ETD-150 for high strength. Both offer excellent machinability and are available on eBay.

I was going to volunteer 4140 but when I looked up ETD-150 I find it is a near 4140 steel that has been drawn at elevated temperatures--which makes it more suitable for tensile applications.

{Learn something new every day.}

 

[dirty tools]

Contact
smokestack.com

 

[MrWhoopee]

I was going to volunteer 4140 but when I looked up ETD-150 I find it is a near 4140 steel that has been drawn at elevated temperatures--which makes it more suitable for tensile applications.

{Learn something new every day.}

At Rc 32 min and 150k tensile, it is roughly equivalent to 4140 quenched and tempered, but it has sulfur, tellurium or selenium added for improved machinability. I'm surprised more people aren't familiar with it.

http://www.niagaralasalle.com/pdf/etd150casestudies.pdf

 

[Martin W]

Are these head bolts for a hit and miss engine? I agree the ETD150 is best.
Cheers
Martin

 

[fixit]

Could you start with a bigger version of an existing bolt and machine it down to what you need? Might save some time.

Store bought common bolts are crap to machine, just my opinion