Shortening a spring

[Lightyear]

Morning - how easy is it to shorten a spring and not muck it up ??

I have done a search on here and have read about people doing it, but I never have and just wondered about attempting it and am worried about getting the end nicely squared off again!

Cheers.

[Rapidnick]

I found it quite easy if you have an angle grinder and power file. Whatever you use don't be tempted to cut too much off at once-at the most one coil at a time. Flatten the cut end with the electric file/angle grinder, replace and test.
Trying to cut a tempered steel spring with a saw or hand cutting tools is quite an effort-you really do need power tools not just to reduce the effort but also to make a really neat job.
Good luck.

[Lightyear]

Thanks for that.

The other threads I had read had suggested the need to use heat to bend in the end to be flattened ! I have an angle grinder and if I can use that then I think I may be in business.

I have the old spring I took out to try on first before I try and shorten the Venom jobby.

Cheers.

[Gwylan]

Getting the end face flat again is the hardest bit, as you say, heat the last bit to bend it a bit, then use a bench grinder, and wet and dry to finish it off.
You can shorten it a small amount by heating the last 3 coils or so red hot to destroy the temper, and pushing the end onto a steel plate. This keeps the end, but means you have to retemper it.

Gus

[Lightyear]

I was really hoping to get away with just cutting and angle grinding the end flat without recourse to heat !

We only have leccy where we live and no gas !!!

Ta.

[Rob M]

Gwylan:

I have shortened a couple of springs and heated them up to close up the last couple of coils, then ground the ends flat and polished with wet&dry. I didn't re-temper them though, and they both seem to be working fine... Both in medium-powered pistols though, not rifles.

How would you go about re-tempering a spring?

Cheers for any info!

Rob M

[electric sheep]

It's never made any difference to performance regardless of a flat coil or angle if a top hat is fitted. The whole spring will still be free to rotate and the dynamic nature of an uncoiling spring is not compromised. It may not look as good but don't worry, if the top hat will rotate with ease leave it and just polish off the sharp edge.

[Gwylan]

Rob M... come to think of it, I didn't retemper that one. What I have done in the past with an old spring is to heat to dull red, and quench in water, then heat to straw yellow, and quench in oil. It might be difficult to do only part of a spring, as the heat would conduct down the length, and muck the rest up.

Gus

[Rapidnick]

For flattening the end I have found a power file to be better than an angle grinder. I appreciate the tempering point as the metal does get very hot but I haven't had a problem just using the spring after using a power file on it.