SFIC and ball bearings

[Raymond]

Has anyone else tried or thought of putting a few ball bearings in the spaces closest to the shoulder to improve wear resistance?

Turns out the 7/64" bearing is .109" and the SFIC pins are .108". This is so close that they work perfectly. The 7/64 bearing is almost exactly the length of a #0 pin and works perfectly.

So, the down side is that pick resistance goes down very fast. You dont even need a comb pick, just raise the ball to the top of the keyway. All spaces with a ball work with a 0 cut.

If you use the ball bearing, the next pin is the size of the cut required. For example: If you want a 4 cut, use one ball bearing and one #4 top pin. Pin the control and top normally. This space will now work with cuts 0 and 4.

This might be a solution for a lower security, environmental type situation. With a 7 pin core you could use 2-3 balls and still have 4-5 pins pinned normally for security.

[tomasfuk]

I do it often but with the Euro profile cylinders.
The pins are of ø 3.0-3.1 mm thus I use balls ø3.0
The shortest key pin #0 is 4.5-4.7 mm high thus I add a master pin of an effective height ≥ 1.5 mm. (For this purpose I make special pins which have one end shaped exactly as standard key pins, but the other end is flat with a dimple 0.5-0.7 mm deep. Such a pin is being led in his path better as it is longer, 2.2 mm at least, being centered by the ball too).

This mod makes a new shear line but as it is deeper by 4 numbers, it is not so easy to pick. Even where the security is important, I put a higher top pin there - so high one that the new shear line cannot be reached (the total length of the compressed spring + top pin + "master" pin > top pin channel depth).
I suppose that SPP is more difficult with such pins because the tip of the pick will slip on the tip of the key pin now.

Where the climate conditions are friendly (no water condensation), I use hardened balls for ball bearings. Where the climate conditions are not so good, I use stainless steel balls.

I did it with 15-20 double cylinders yet - no problem occured.

[tomasfuk]

...This mod makes a new shear line but as it is deeper by 4 numbers...

I mean by 4 numbers deeper than #0 (i.e., #-4).

[MatrixBlackRock]

Has anyone else tried or thought of putting a few ball bearings in the spaces closest to the shoulder to improve wear resistance?

Do you think the nickel silver pins wear that fast to warrant such a mod?

Wayne

[tomasfuk]

When it comes to classic pin tumblers, I have met key pins from hardened steel, brass and nickel coated brass only. FAB, ASSA Abloy FAB, KABA GEGE, EVVA, GUARD, EVVA GUARD...

[MatrixBlackRock]

When it comes to classic pin tumblers, I have met key pins from hardened steel, brass and nickel coated brass only. FAB, ASSA Abloy FAB, KABA GEGE, EVVA, GUARD, EVVA GUARD...

My scope is limited as I only work with Best and their lower pins unless repined improperly are nickel silver, now if the pins are swapped out for brass, then the keys need to be swapped out from nickel silver to brass as well.

Wayne

[Sinifar]

Back in the day, Corbin and Russwin used to use ball bearings in their locks. Yale used to have striated pins, with grooves cut into the lower pins along with spool top pins for pick resistance. Never saw Best with balls in them.

But the way, there is a Best "1" top pin, it is .012 thick. I am not sure if Lab makes those anymore, but ages ago I had several vials of them just in case ... never used them, but now make a super souvenir of days gone by.

Sinifar

[Raymond]

The most worn down cores I have ever seen came off a drug cart used by nurses. The first three pins on a 6-pin core were nearly two full depths off. The tip of the keys were off about 1/2 depth and the groove in the pins made up the rest. Talk about worn out. The nurses must use that key 120 times per shift. Even the tip ramp of the key was worn back even with the tip stop. I hadn' thought about using the bearings then.

[jeffmoss26]

We had some very worn out keys at the Student Union...they got used all day, every day by student workers who did not really care.