Spend £4.50 and buy a set of 3 different length ones, the longest 10″. No point in wasting time. Noel

On 11 April 2025 at 11:01 Howard Lewis Said:

As you can see from the extension that you have, the spring and ball were inserted into the hole, before a hollow punch was used to peen over material around the entrance to the hole.

Certainly, that’s how I make them; I this case, I think I used a press, rather than a hammer and punch.

This is a ½” – ¾” adaptor, which I’ve never seen for sale; I bought a ¾” ratchet second hand, without a drive piece.
Made out of some EN19 I had in stock; the surface finish is rather better than it appears, as the flash highlighted the markings.
Make sure you leave enough clearance in the hole around the ball, as grit can gain entry and jam it up.

Bill

Not sure how that will work Peter ? The OP wants a spring loaded ball. Noel.

On 11 April 2025 at 12:58 noel shelley Said:

Not sure how that will work Peter ? The OP wants a spring loaded ball. Noel.

Verbatim quote from the ebay listing:

The ball point set screw is composed of spring, ball plunger and shell. It is mainly used to fix on mechanical equipment that does not require protruding ends.
– The ball point set screw is slightly elastic, allowing slight adjustments without loosening the screws, reducing surface wear. Even if the load is unbalanced, the internal spring can receive the load evenly.

MichaelG.

It is very easy to achieve this. Drill a blind hole for ball and spring. Make up a hard rod such as the stock end of a broken drill with about 135 degree included angle. Load the spring and ball, then press on the ball with the point of the rod which will push it in, then the rod is able to be self centred on the hole. Finally apply pressure with enough force to distort top of hole to retain ball. May need to experiment to get dimensions exactly right.