Repairing an Antique Lockset Return Spring

Given our house is 130 year old, it is not unexpected that some things are going to start wearing out. This is particularly true of mechanical components that get regular use such as locksets. The continued used eventually causes things like springs to fail due to metal fatigue. This entry discusses repairing an antique lockset return spring. I know this isn’t strictly a woodworking project but certainly peripherally related to restoration so I’ll include it in the category.

The lockset on the door leading from our kitchen to our mudroom began to fail to remain closed. The bolt was no longer extending automatically after the doorknob was turned,

As a result, it would no longer engage with the strike plate and the door would just swing open.

Diagnosing the Problem

Removing the lockset for repair requires removing one of the doorknobs and sliding the spindle out of the lockset. Then only two screws need to be removed from the face of the lockset and it slides right out.

Once you have the lockset out, there is a single screw that holds the side cover on.

Removing the cover lets you see the interior of the lockset.

If you are wondering what the white is, it is lithium grease. My first thought was that the mechanism simply needed lubrication but this was not the case. The actual problem was that the spring that returned the bolt to its extended position had failed. You can see the spring, a thin strip of spring steel, in both the relaxed and tension state at the bottom of case in the following images.

Repairing the Spring

Now here is the problem, how do you find a replacement spring for a 130 year old lockset. I’m sure that somewhere on the interwebs you could find someone that sells replacements. I’m cheap and impatient, however, so I went looking for something I had on hand instead. It turns out that an old hacksaw blade is the same thickness and spring as the original piece.

A quick trip to the grinder and I have a replacement piece for the lockset.

I then slip this into place in the lockset case and close it back up.

With the new spring in place, the lockset was back in working order. I expect that we can get another 130 years of use out of it now.

Thanks for reading!