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From: "Jim Wilkins" <muratlanne@gmail.com>
Newsgroups: rec.crafts.metalworking
Subject: Re: Geometric Self Opening Die Heads
Date: Tue, 16 Jul 2024 22:30:47 -0400
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"Bob La Londe"  wrote in message news:v770jj$1fv4f$1@dont-email.me...

On 7/16/2024 4:33 PM, Jim Wilkins wrote:

Yeah, at a little over 2 bucks a piece for the cheapest ones in the
right size I'd modify hardware store bolts too.

https://www.mcmaster.com/products/bolts/fastener-strength-grade-class~sae-grade-8/thread-size~3-8-16/length~4-1-2/
Bob La Londe
--------------------------------
I gave the approximate length for simplicity, actually they are threaded 
just far enough to keep all shear loading on the full diameter shank with 
only enough axial clearance to minimize cantilever loading and avoid binding 
when the locking flange nut is snugged. I may have to leave more shank to 
fit the stronger chain. The Grade 2 4-1/2" bolts didn't have quite enough 
shank length and one showed thread damage when removed.

This is more fussing than I would design into a commercial product unless 
higher performance justified it. I've been the tech doing that custom 
adjusting, like cutting coax cables to length to match the propagation 
delays, the timing error tolerance was equivalent to around 1/16". They were 
for a machine that tested computer memory chips for speed and errors before 
they were cut from the wafer.

At the start of WW2 when we took on the manufacture of foreign designs, the 
Merlin engine and Bofors AA gun, we found that hand fitting was still common 
in Europe.