Yes, reversible top pieces screwed on

… I think Pratt Burnerd calls them ‘American Style’ or some-such

… Saves having to do matching scrollwork on two sets.

MichaelG.

I have a similar style chuck (160mm one) from Chester. The jaws do reverse and soft jaws are available.

I converted a set of soft jaws to a master set that takes my own made tops ( I use soft jaws quite a lot!).

Jim

Looks like an ideal chuck to take soft jaws! You have to make your own, of course.

Howard

How many of us remove the spring from the chuck key?

I believe they are called slot & tenon and if you have a mill, it would be easy to make tops in mild steel or aluminium to bolt on to the master base jaws. Because of the bolt together design, they project further from the face of the chuck than one piece jaws.

If you get all the sizes of the required jaws, then someone like Rotagrip or Thame Workholding may be able to help.

I have allways manged to find soft jaws for all my chucks. They are usually around £30-£45 a set, I then simply turn these in to "master" jaws and make up bolt on tops

Jim

Me.

Tony

Really. Why?

Big employers are hot on best-practice because they've been sued, prosecuted, had expensive machines damaged, paid hefty legal fees, and then been walloped with increased insurance premiums! Once you get beyond near misses and trivial incidents, even small accidents cost tens of thousands. A fatality is likely to cost millions.

Model Engineering has an excellent safety record. But I don't see any advantage in deliberately defeating basic safety features, especially anything like a chuck spring that only slows me down by a few seconds. Real men take up wood-working and start by removing all those inconvenient power-saw guards. Chop, chop!

Dave

Big employers are hot on best-practice because they've been sued, prosecuted, had expensive machines damaged, paid hefty legal fees, and then been walloped with increased insurance premiums!

I have been in a great many engineering workshops in the last 43 years & have yet to see a spring on a chuck key in any of them. A spring is no substitute for safe working practice. At the Apprentice training school I did my "First year off the job" training at, the Lord help you if you were lax enough to leave a chuck key in the chuck. Those who did so did not do so a second time !

Nigel B

Funny you should mention the other type of top jaws, Dave, these serrated with 1/16" X 90 degree pointed jaws for a 6 1/2" Pratt chuck came through the post this morning. I was lucky and put in the only bid on ebay, and got them for £8.75 including postage. I looked up the Thame code, AJ06 before bidding.

I have lots of the serrated jaw sets, some were for larger chucks. You can get larger 1/16" serrated jaws to fit if you make custom tee nuts with the threads and pitch to suit the bigger jaws. the edges of the jaws where the serrations are may have to be narrowed slightly. I also have two sets of hard jaws, one standard and one a size larger. They did not run very well, and were slightly bellmouthed, so they got ground and run dead true now. I also had to number them to match properly. The underside of the larger ones had to be narrowed slightly, and as they are hard, I used a solid carbide end mill on them.. You sometimes get job lots of used ones on ebay really cheap, which is where mine came from, some well used and some nearly new.