I finally got around to posting about a set of screw machine drill bits that I bought last fall. I purchased them from Amazon.com for about $80. I had a commercial job that paid me real well and I figured that if I could skip the operation of spotting before drilling I could save a lot of time, at least for non critical locations like bolt holes . That turned out to be the case and the bits easily paid for themselves in time savings on that job alone.
When I started using them I was very impressed with the quality. Very bright ground finish. They cut cold rolled like butter, sharp as can be. Then one day as I was drilling a 25/64" hole I noticed what looked like clearance around the bit. Pulled the bit out and checked it with a caliper and it measured about .410". Sure enough I dropped a 13/32 bit into the hole and it was wobbly. Fortunately the hole was a clearance hole for a 3/8 screw so it wasn't a big deal but if it had been for a reamed hole I would have been screwed.
Next time I used one of the bits I checked the hole and it was oversize too. Pretty much all of them drilled anywhere from .010 to .040 oversize. How a USA based company would let crap like that out the door is beyond me. The label says USA on it. It isn't like these were ground by hand. I could almost understand if one bit was off but the whole set? These folks are making harbor freight and the Chinese tools look better all the time.
I looked for quite a while before I could even find a contact for Chicago Latrobe and called them to explain my problem. They told me to send them back to Amazon for a refund or exchange. By that time I had sharpened probably 1/3 of them and didn't want to take the time to send them back and possibly get another batch of crap bits so I just kept them. The person on the phone at Chicago Latrobe didn't seem to be very concerned, which kind of shocked me. Eventually I will have a set of sharp bits that drill to size, as I have an industrial sharpener that weighs about 500#.
The set of bits:
Anyone else had any experience with these? We used Chicago Latrobe tooling a lot when I was still working and their quality USED to be stellar.