What is this?

[Tundraman]

I have recently recieved a Buck 110 Smoke Jumper CPM-154 from SKBlades and was drawn to this immediately. I just picked up what I thought was the new knife box, but ended up being a 110 Lite that was purchased quickly and used for a quick excursion when I was knifeless. Bad I know. But the Smoke Jumper and the Lite both have this bump or nub where the back of the blade meets the spring. The Jumper only on the spring but the Lite is on both. All my knives are ground flat here except these two. Usually well enough where you can barely see the line seperating the two. Its not enough to worry about for me but curious as to why they weren't ground flat there.

 

[DeSotoSky]

This question pops up regularly. The humps are because a sharp corner can not be fine blanked. Glass filled nylon will burn if sanded. Wood /metal handles or the Valox handles do not.

 

[Tundraman]

Ok. That makes sense. Thanks.

 

[Lesknife]

I have filed mine flat on one of my LTs with a diamond file. I’ve heard several people doing this if the bump is bothersome to them. It really doesn’t bother me but I was curious if it made a difference and it is very minimal.

 

[Bastler]

Just a suggestion; if you do grind the nub, open the knife halfway to elevate the rocker bar, so you don't file the handle too.

 

[Lesknife]

Just a suggestion; if you do grind the nub, open the knife halfway to elevate the rocker bar, so you don't file the handle too.

You have to be careful with grinding. If the metal gets hot it can melt the FRN handle material. That’s why I recommend using a diamond file. I do like your idea of opening the blade part way to allow clearance to the handle.