Case hardening 4140 steel shims

[RyanNZ]

Hi everyone, I need to make sixteen 3.5mm x 11.5mm shims for lifters in a Subaru. My problem is heat treating the steel to harden it to withstand wear and impact.

- From the research I've made so far, I've figured that I need to induction harden the shims, is this correct?

- If so, what is the best way about doing it in a workshop (with access to gas torches etc)?

- And because I am machining the shims to .01mm accuracy, do I heat treat the shims when they are at their rough size of 4mm, or do I heat treat once they are at their final machined size?

Many many thanks!!

 

[swall]

You will need to surface grind after heat treat, assuming you have the wherewithal to procure suitable material, machine the parts and have the heat treating performed.

 

[arunmrao]

You need to harden them,when you are close to your finished size. You need to then surface grind them to the final dimension. Take the help of an experienced heat treater and machinist.

 

[RyanNZ]

Thanks everyone, have machined shims and are in vehicle running well.