3/32 drill bits

[GLDOYLE]

My 3/32 drill bits from Texas knifemaker supply are .092 , the same as my pins . My 3/32 straight reamer is .084 [ smaller than bits ? ? ? ] , and 3/32 drill bits from Dewalt , Bosch , and Milwaukee all measure.089 . Why are they all different from the ones from T K S . Can you only get the right ones from a knife supply house? Seems like a 3/32 bit would be the same no matter whos it was .
Can someone enlighten me as to why ?

[Ed Tipton]

GLDoyle....The sizes of drill bits are nominal sizes. Unless you purchase a precision bit from a reputable mfr., then "nominal" is about as good as it gets. Even if the drill stock is correctly sized, even a slight mis-grind will result in an oversized hole. Reamers on the other hand, are far more precise. You would probably be well served to drill using a smaller bit which ....again...is likely to result in another oversized hole....and then ream to achieve the final hole size. Even with a "precision" drill bit, it is unlikely to get accuracy to .001 since the bit can "Walk" when it is started (even when center punched). Pretty much, if you want an accurate sized hole, the only way to get it consistantly is to ream it.

[DaveL]

Just use a #41 bit and be okay with pins

[Don Robinson]

To measure a drill or reamer, revolve it in your fingers while holding calipers. The largest measurement is the size.

All drills are tapered to relieve the friction while drilling. Anybody's drills are the same diameter at the tip, then they taper smaller toward the shank. The shank is smaller than the tip of the bit.

All drills are made to precision sizes, same as a reamer. The size hole they make depends on your knowledge of using it.

[Don Robinson]

I should have posted this before.

Always use a cutting fluid on a reamer, otherwise it will cut oversize. Never use lubricating oil on a cutting tool or it will wander. I use tapping fluid on everything including drills and reamers.

So: to cut on size, use cutting oil.

To cut oversize use water or nothing.

A drill usually cuts a few thousandths oversize.


I never use carbide. I use import high speed steel tools.

Leave .005" to .015" for a reamer to remove depending on the size of the reamer.

[John I Shore]

Originally Posted by GLDOYLE

My 3/32 drill bits from Texas knifemaker supply are .092 , the same as my pins . My 3/32 straight reamer is .084 [ smaller than bits ? ? ? ] , and 3/32 drill bits from Dewalt , Bosch , and Milwaukee all measure.089 . Why are they all different from the ones from T K S . Can you only get the right ones from a knife supply house? Seems like a 3/32 bit would be the same no matter whos it was .
Can someone enlighten me as to why ?

Usually can't put a 3/32 (use any size) pin in a 3/32 hole. Drills are not that accurate, nor do they make a round hole, you can never get a round hole by drilling, you can come close with reaming, but remember, you must have clearance.
In our shop we use metric drills that fraction down to a 10th of a millimeter so we can drill the proper size hole if we are not reaming, (example: for a 1/4" Thong Tube we use a 6.4mm drill, better fit than using an F Drill).
When it comes to drills, buy the good stuff, pays off in the long run, especially when you resharpen them.
Also remember to mic your pins, unless they are precision ground then you only have an idea of their size. Good rule of thumb is: Measure everything.

Hope this helps:

John I.

[Ed Caffrey]

Here's some simply info that might be useful when installing pins....

Pin Size.........................Drill bit size

1/16" pin..................................#52
3/32" pin..................................#41
1/18" pin..................................#30


As has been mentioned, there is also the option of figuring out the decimal equivalent of metric bits and using them.....there are several instances(mostly when building folders) where I choose the metric route simply because there is not an SAE bit that does what I want.

[DaveL]

Thank you Ed this how it is done to use a slight oversize bit,
.