source for left-hand thread drill chuck locking screws?
 

I recently bought a Jacobs keyless chuck from replace the keyed one on my old Bosch GSB 9.6 drill,
unfortunately the left-hand threaded locking screw from the old chuck isn't long enough - any idea
where I can get a longer screw - it needs to be about 35mm long (end to end)?
Not sure the nominal thread size - I'd guess about 1/4"