OK, so my new Astro metric tap and die arrived last week and has set on my bench. Well last night i needed a longer bolt. Anyway the threaded bolt was 1.125. I checked with the tool that was included with the set.The die went down the threaded part with no effort. It finally started cutting the bolt. Yes I backed it out every so often.After about an inch, I removed the die. The threads were cut however, not as deep as the original threads on the bolt.Am I doing something wrong? I used 30 wt oil as lube. The die cut fine but as I mentioned not as deeply as the original threads into the bolt. Common sense tells that this would affect the strength of the bolt when tightened.Any suggestions? Thanks, Ken
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Tap and Die question
- Thread starter Kenskip1
- Start date
cvairwerks
Well-known member
The die needs to be adjusted in the handle to provide the appropriate thread depth for the class of fit you want.
Looks like the Astro’s are not adjustable....
Looks like the Astro’s are not adjustable....
Last edited:
Wamsutta
Well-known member
It's not cutting as deep because you're now trying to cut threads into a heat treated, hardened bolt. The original threads were cut prior to heat treatment when the metal was still soft.
marinusdees
Well-known member
The original threads were probably rolled, not cut. The unthreaded part of a bolt is typically larger in diameter than the specified maximum for the die.It's not cutting as deep because you're now trying to cut threads into a heat treated, hardened bolt. The original threads were cut prior to heat treatment when the metal was still soft.
Last edited:
DFB
Well-known member
Ya round adjustable dies have the capability for over and undercutting threads vs a fixed hex die
But all might depend on how the bolt was made
If it was extrusion rolled thread formed the unthreaded portion of the bolt will have been smaller
But all might depend on how the bolt was made
If it was extrusion rolled thread formed the unthreaded portion of the bolt will have been smaller
MetricTech
Well-known member
Cutting the unthreaded shank of a bolt does not make it match the rest of the bolt exactly it just makes it workable. This is not news
We’ve all been there I think. She won’t be pretty but it’ll work in a pinch
Metric Tech
toplessHO
Well-known member
less material removed makes it a little stronger too.
kinda like running a tap to 75%
kinda like running a tap to 75%
WaterBoyz
Well-known member
Ya round adjustable dies have the capability for over and undercutting threads vs a fixed hex die
But all might depend on how the bolt was made
If it was extrusion rolled thread formed the unthreaded portion of the bolt will have been smaller
I knew sorta but the video was interesting for my simple mind......what's left of it anyway.