Bar Clamps Build Process

6/5/2021

As I've decided to attach the ends to the bars with M12 screws instead of welding them on as Neil Paskin did, I have to include an M12 tapped hole in each end of the bars. There are a few ways I could have done this:

• File two corners off an M12 nut, somehow hold it central in the end of the bar and weld into place.
• Weld some steel into the end of the bar, then drill into the end (probably in the lathe) and tap M12.
• Make some 20 mm square inserts with a central hole tapped M12.

The first option has the advantage that it doesn't need any special tools. The second option has the advantage that it makes sure that the tapped hole is central with respect to the box section. The third option is (I think) the quickest, so that's what I'm going with! I've got a 250 mm length of some finest grade skipium that happens to be the right size. I decided that the easiest approach was to cut this into 60 mm lengths then drill and tap each length using the lathe. The pieces could then be cut up into 10 mm lengths. I don't care too much about the finish on the face as I'm going to be welding over it anyway.

This photo shows one of the 60 mm lengths after I've drilled it 10.5 mm and tapped it (with a spiral flute tap) M12 under power. After getting the first bar into the chuck and centred properly, I marked two of the jaws with a marker pen so I could just undo those two jaws, swap the bars over and tighten the same two jaws. This won't result in absolute precision of the hole in the centre of the bars, but it really doesn't need to be precise for this application.

This photo shows three of the bars after they've been removed from the lathe chuck and one after it has been cut up into slices. The little vice on the left-hand side of the photo hasn't been used for a long time: I used to use it for holding stuff down on my mini-lathe when trying to do milling operations. Since getting my little milling machine, it hasn't been out much.

For this operation the little vice was really useful for holding the short lengths of bar in the bandsaw vice so that they could be chopped up into little square nuts.

This photo shows all of the resulting inserts. I need two per bar, so this is way more than I need for the eight clamps I'm planning to make, but I figured I might as well cut the whole bit of steel up and then I can keep the spares in case I want any other lengths in the future.

Page Navigation:

This website is free, but costs me money to run. If you'd like to support this site, please consider making a small donation or sending me a message to let me know what you liked or found useful.