Torque on Bridgeport R8

Use a standard size 3/4" wrench and put the brake on . Tighten it up by feel . Never had an end mill pull out in 43 years . If it worries you , go with an end mill holder .
 
mmcmdl said:
Use a standard size 3/4" wrench and put the brake on . Tighten it up by feel . Never had an end mill pull out in 43 years . If it worries you , go with an end mill holder .
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Yes, 43 years experience is better then any torque wrench. Here's my problem. I'm looking for a number. Many numbers would be better and I can take the average. However I'm beginning to understand that people don't use a number. They don't have a clue what the torque is and they don't care. They know what works. I'm good with that. Thanks
 
Blip and a half, on a 3/8 drive impact. If I had to guess I'd say about 50ft.lbs.. Mike
 
I'm all over the place when it comes to torque. For instance, I would tighten the draw bar a lot tighter
if using a huge drill bit compared to a 1/8 inch end mill used for some tiny work. It has to be as tight
as the application requires and that is enough.
 
Torchmach has a fun whitepaper looking at torque and pullout. If my meat-archive is right... including R8.

Sent from my SM-G892A using Tapatalk
 
dfwilbanks said:
Yes, 43 years experience is better then any torque wrench. Here's my problem. I'm looking for a number. Many numbers would be better and I can take the average. However I'm beginning to understand that people don't use a number. They don't have a clue what the torque is and they don't care. They know what works. I'm good with that. Thanks
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I wouldn't say "they don't have a clue". Over the years most of us have gained enough experience to know what 40 ft. lbs. of torque feels like when using a standard 3/4" wrench. We may not always, or ever hit 41 ft. lbs. on the head exactly, but we know we're within a couple pounds either way.

As for the torque spec of 41 ft. lbs. on a 7/16-20 thread it's the number that will provide the most holding power without damaging either the internal or external thread. You can tighten it much tighter if you wish, but the down side is that it won't last. To my knowledge the drawbar in my Bridgeport is the original. That's 48 years of tightening and loosening it with out damage.

As for an end mill pulling out I've never had it happen on my machine.
 
How does a mechanic explain to an engineer what "snug" is? I have a clue what torque is, but it's a multi variable problem that is most simply solved by the application of "enough" torque.

I work in a world of measurements, specifications, and numbers. One thing I'm sure of at this point is that the numbers don't matter. I rate the effectiveness of a system based on whether it meets the requirements. If I require a tool not to move on my mill while I work, I'm going to give it enough torque to be "effective". I think this is the answer that has been the lowest common denominator in this thread.
 
projectnut said:
I wouldn't say "they don't have a clue". Over the years most of us have gained enough experience to know what 40 ft. lbs. of torque feels like when using a standard 3/4" wrench. We may not always, or ever hit 41 ft. lbs. on the head exactly, but we know we're within a couple pounds either way.

As for the torque spec of 41 ft. lbs. on a 7/16-20 thread it's the number that will provide the most holding power without damaging either the internal or external thread. You can tighten it much tighter if you wish, but the down side is that it won't last. To my knowledge the drawbar in my Bridgeport is the original. That's 48 years of tightening and loosening it with out damage.

As for an end mill pulling out I've never had it happen on my machine.
Click to expand...
Well "don't have a clue" wasn't the way to put it. Don't need to know is better.
 
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