When to drill pin holes.

[DARblades]

I've been drilling pin holes after heat treat because I'm concerned about distortion. I have seen many makers drill before heat treat for obvious reasons. I would rather drill soft steel but am worried that the size will change in the heat treat process. Let me know your thoughts.

 

[Travis Talboys]

I always drill prior to heat treatment. You can always true up the holes later if needed, and it won't be as big of a headache as trying to drill hardened steal.

 

[wayneblocker5369]

Your holes should be a little over sized anyhow.

 

[Richard338]

I wouldn't worry about distortion on a slightly oversized hole. I often do threaded tangs and never have had enough distortion to be a problem.

 

[Hengelo_77]

Up to 2mm I drill 0,05mm over size, over 2mm I just tap it in

 

[daizee]

Drill, countersink, ream (or at least re-drill) before heat. Make sure you don't have chips or grinding swarf in the holes when you're cleaning up for heat-treat. Easier to sand down pin stock (or drill oversize) than to drill through hard steel.

 

[Drew Riley]

I just don't think it's that big of an issue with the sizes of parts and holes that we're dealing with. I might have to clean a little scale out of a hole on occasion, but like others have said, the tolerance of the pins and holes should allow for some minor discrepancies here and there.

Worst case, have a carbide reamer, a barrel lap, or even just a drill bit on hand to do a quick cleanup of the hole.

 

[DARblades]

Thanks all for the feed back. I do appreciate it! I'm going to dill before HT on my current batch.

 

[E.Carlson]

I drill my holes right after I profile the blade as part of the profiling process. All holes are in before any bevel grinding is done.
This tends to eliminate any encounters with the dreaded whirling blade of death.

 

[wayneblocker5369]

What Ecarlson said, nothing makes me cringe more than someone drilling an just holding the blade with there bare hand!!! Safety first.

 

[Horsewright]

Oh heck yeah! After profiling and before grinding bevels. I also will grind off any burrs from drilling and straighten any tweaked blades before grinding.

Ready to grind bevels.