Questions About 6" Bridgeport Mill Vise

GarageGuy

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I picked up a 6" Bridgeport mill vise at an industrial garage sale for $50. It works perfectly, has little wear, and only one pockmark. The only thing wrong with it is the jaws are missing. I can make new ones, but I have a couple questions: What kind of steel is best suited for mill vise jaws? Should the steel be hardened, or stay soft? I would like them to be as close to OEM as I can. If I want soft jaws later on, I can make those as well.

Thanks in advance!

GG
 
Soft, and I've found out the hard way! Twice, sadly. :( (soft plumbers solder in the accident location fills in the gouge nicely)

If they're hardened they can ruin the endmill, and the softness (I would think) would allow it to grab the part slightly better than hardened.
 
I am using a 6" Bridgeport vise on my mill. I restored it. It too was missing the jaws. Other than that, it mostly just looked really bad. I disassembled and cleaned it up and stripped the paint. The vise has box ways, like higher end milling machine saddles. You can scrape the sole and scrape the bottoms of the extended sides of the movable jaws (where the boxing plates mount) to tighten up the fit. My beat up (50 year old?) vise still had only .0015" of vertical clearance in the worst corner, with a little work it is now at .0005" clearance along the entire bed. I have used Kurt vises, and my Bridgeport holds work down without the movable jaw and work rising better that the Kurt does. I also like the solid sole of the vise, no voids for stuff to fall into. The acme screw is high and exposed and it is easy to keep it and the bearings clean and oiled. Those old Bridgeport vises are very nicely made, quality tools.

I made the jaws from 1/2 x 2" 1018 cold rolled bar stock and finish machined them in place. I prefer softer jaws over hardened ones. They grip better. They can easily be re-machined if they get dinged and are also easily and cheaply replaced. I bought a 3'+ bar of the 1018 and that is likely a lifetime supply of vise jaws.

I also made keys for the slots under the vise and made them a snug fit in both the vise and the table slots. With a little wiggle the vise drops gently onto the table and into the slots and is within less than .001" of perfect tram over 6" by just bolting it down. A simple tap with the palm of my hand in the correct direction before tightening it down gives less than .0005" runout in 6", without using an indicator at all.

I guess you can tell that I am happy with it...
 
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Thank you all for the advice, and also for the photos, Bob. That is exactly the vise I have. I installed a new cylinder nut in a friend's vise last fall because it stripped out, but the cylinder nut and lead screw in mine look perfect.

Mild steel for the every day jaws. I have Nylon, aluminum, and Delrin laying around for soft jaws later on. I don't know if I will paint my vise or not. I'll probably just clean it up and oil it well. That way it will match everything else I have.

Happy New Year!

Sent using Tapatalk from someplace deep inside the garage
 
Should the steel be hardened, or stay soft? I would like them to be as close to OEM as I can. If I want soft jaws later on, I can make those as well.

Thanks in advance!

GG

Do plan on using this vice 40+ hours per week?

If not soft jaws would be a more useful option for you, for what reason would you find "OEM" jaws desirable outside of maintaining it as an antique collectable tool?
 
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