Was watching an episode of Gearz the other night and Stacey had a short bit on the difference of a tap and die set vs. thread chasers. I thought at first, what, another hard sell for a sponsor. But I thought about it and remembered a few occasions where I would use a regular die on a bolt to clean it up and ended up with a nut that was a little loose.
Apparently typical tap and die sets are for new holes. The tools in such sets can slightly undercut the original threads and you have less thread surface in bearing which can invite stripping or galling. So I'm about to spring for a set of chasers. I found a deal on some individual sets online since I already have a regular set of tap and dies.
What's your experience with these? Maybe this is common knowledge in the industry and I am late to the party once again.
Yup, I have a MAC set that I have had for 20+ years that I purchased when I was working on airplanes. I have a thread file and rotary wire brush I can use on bolts and studs. I came across this metric set on eBay and with over 75 sold, I figured it was a good product and worth a gamble.
Although this seller only had this metric set, they arrived in a package with the manufactureres info. I found them online with SAE coarse and fine thread for $10-15 a set. They even have them for left handed threads.
I was in cutting tools for a lot of years; retired now; (1) There is a "class" of threads for taps and also dies. The "class" referes to the "fit", how close of tolerance do you want. (2) Probably most of all the taps & dies you buy at Home Depot or Sears, etc will not even have a "class" shown on the die or tap. To most everyone at home doing a hole once in awhile it doesen't matter how close the tolerance is. Machinist and mostly on the production line it does matter. Most people just use a tap or die to "chase" the threads. If you want a really good tap & or die go to a tool distributer that sells to the industry, and I'm not talking about Harbor Freight!
Agreed - you know there are a few things I wont buy from Harbor Freight and tap and die sets are one of them. Add to the list drill bits and anything that would require preimum grade or hardened tool steel. Forunately this company is in the US and they clim their tools are US made as well. Hopefully they will work well enough to deserve a spot in my tool box.
Most, but not all of the tool & die sets and drill bits you see locally in Home Depot, Sears, Harbor Freight, kinda places are made of carbon steel. If you want a GOOD set of those, you want to look for HSS; there are several grades of HSS also; if you want the BEST, look for M7 or M42. Also, Home Depot & Sears will sell a lot of M2. Don't buy that unless all you want to do is drill a hole!
I've used taps and dies for chasing for years and more often than not the fit afterwards would be too loose. I finally broke down and bought a complete metric/standard Cornwell Tools $95 rethreader set. Ruined me. I later bought another set for home so I wouldn't have to carry them back and forth.
I just read about using chasers with my ARP head bolts I just bought and installed. All I could find locally was a tap, so I went with that. Bought a $6 tap from Car Quest to clean out the rusty head bolt holes. Worked fine, but next time I'll plan ahead and order a chase to clean up things.
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