Recommend a pair of these L wrenches, easy to EDC in most sheaths Torx Tamper Resistant L-Key Tr10x51mm, by Wiha • Precision Machined exact fit Security Torx Tips. • Made from Wiha exclusive CRM-72 tool steel. • Black Oxide Finish. • Through hardened for extreme durability. • Made In Germany(Image removed from quote.)
You could just snap those little pins on the inside off and you have a regular torx screw
FYI, the pivot size s 7/32 if you were going to buy new knife pivots and use washers.
Oh, sorry about that. You wanted the actual screw. Maybe you should get a normal screw and forget the security version, would be easier to locate and probably a lot cheaper. There's a bolt that is flattened on one side that does not turn. The other side has a screw that will turn, should turn fairly easily in fact.