drilling and tapping cast iron

Re: drilling and tapping cast iron

Don Orr

My limited experience was that cast iron drills and taps more easily than steel. Take your time and use a good lubricant.

easiest of any metal

Bill Tindall, E.Tn.

The carbon in cast iron lubs the tools and they cut without binding. As usual with tapping back the tap periodically to clear chips.

Re: drilling and tapping cast iron

John K Jordan

>>>My limited experience was that cast iron drills and taps more easily than steel. Take your time and use a good lubricant

My experience exactly. I most recently drilled and tapped a hole on my PM3520b to mount a task light and it was very easy. I understand under some circumstances cast iron can develop hard carbides right at the surface but I've never run into that.

JKJ

A little can of tap magic is always welcomed

Dick Coers

A little lube always improves tapping, but cast iron is easy.

Re: drilling and tapping cast iron

Hank Knight

I've done it a bunch. Piece of cake, with or without lubricant. Use a sharp drill bit to get a good crisp entry. If you dimple the iron for a starter, don't hit it hard. Cast iron is easy to break.

Don't know that I'd go that far...

Jason Roehl in Lafayette, IN

...but with HSS taps, it's pretty easy. Not as easy as brass, aluminum or soft copper, though.

I had to drill and re-tap a hole in an engine block once. I had a cheap tap-and-die set from Sears. I twisted the tap. So I asked a machinist friend of mine some advice, and he pointed me in the direction of HSS. I coughed up the dough (~$150 vs. $30 for the Crapsman set), and the new tap was like a hot knife through butter.

Jason

Me either....

John in NM

When I worked in a welding shop, we often had to drill out cast decorative parts to fit on whatever the decorator handed us to make. Sometimes they drilled like butter, sometimes they ruined the drill bit before the hole was done.

I'd say brass or bronze drills and taps better than anything else I've cut, either of those get the title

Thanks everyone.