On Tue, 3 Dec 2019 19:27:39 -0500, Ed Pawlowski wrote:

On 12/3/2019 4:32 PM, TimR wrote:
On Tuesday, December 3, 2019 at 2:39:46 PM UTC-5, Ralph Mowery wrote:

Does a bolt really have much more strength in size 21 than a size 20 in
metric ? I would think that as wrenches/bolts reach around size 12
metric they would go up in steps of 3 to 4 to gain enough to make them
worth while to make.

I'm with you. A lot of machines could use one size bolt versus 4 or 5. Some would be stronger than necessary but it would make repair a lot simpler.


True, but it should have been settled 100 years ago. As long as the
bolts exist the wrenches are needed.

I had that discussion with IBM. We were carrying about 50 different
Allen, Bristol 4&6 flute and Torx wrenches around to deal with basic
screws. It got worse when they threw metrics at us.
The answer was they buy assemblies from vendors and each vendor's
engineer think they have the perfect fastener and none of them agree
what it should be.

I then asked if we had bid specs. Couldn't we tell them what to use.
The answer was no.