Hey guys,
Here at our plant we have some silver deming bits - made in the USA cobalt bits. We don't use them a lot - but today was one of the times we needed them.
One of our employees had to enlarge some 3/8" holes to 7/8" holes. The material was about 3/16" carbon steel. He did this by stepping up bit sizes one at a time. He said all our bits were dull and no good. I look at the bits and all seem sharp - each had a minor damage to the very outside tip of the cutting edge - so maybe that will kill the effectiveness of the bit.
I have read on here that some people say stepping is not necessary and deming bits will not step good - then other people say they have been doing it for 30 years with no issue
Later I tried drilling one of the holes personally going from the 3/8" straight to the 7/8" size. We were using a heavy duty Milwaukee cordless drill. It worked pretty good until we got about half way to three quarters through the thickness and then it slowed down big time. We made it through but it took another 3-4 minutes to make it the rest of the way.
Is there a better way to enlarge holes like this? maybe a different type of bit? still needs done with a hand drill though if possible since we can't use our mag drill on everything - like in this case
Thanks! Eric
Here at our plant we have some silver deming bits - made in the USA cobalt bits. We don't use them a lot - but today was one of the times we needed them.
One of our employees had to enlarge some 3/8" holes to 7/8" holes. The material was about 3/16" carbon steel. He did this by stepping up bit sizes one at a time. He said all our bits were dull and no good. I look at the bits and all seem sharp - each had a minor damage to the very outside tip of the cutting edge - so maybe that will kill the effectiveness of the bit.
I have read on here that some people say stepping is not necessary and deming bits will not step good - then other people say they have been doing it for 30 years with no issue
Later I tried drilling one of the holes personally going from the 3/8" straight to the 7/8" size. We were using a heavy duty Milwaukee cordless drill. It worked pretty good until we got about half way to three quarters through the thickness and then it slowed down big time. We made it through but it took another 3-4 minutes to make it the rest of the way.
Is there a better way to enlarge holes like this? maybe a different type of bit? still needs done with a hand drill though if possible since we can't use our mag drill on everything - like in this case
Thanks! Eric