Frank Hunter
Well-Known Member
Alright...I've been using Corby style fasteners from a variety of sources for a long time. This is a new one...
Countersunk the 1/4" shoulder hole 3/16" inch or so, having already drilled the 3/16" shank through one scale, then the other during glue-up. Pretty standard stuff. This has been plenty of depth for the shoulder for hundreds of these fasteners previously. Well, as I'm grinding them off with a 50g Blaze, I see a little pucker showing up on one side of every single one. Six of them, two matching knives. I took a guess and poked the "pucker" with a drill bit and sure enough it was hollow underneath. Upon further investigation, and some very careful drill press action removing the remnants, I discovered that the internal thread of the female Corby goes nearly 1/4" up into the shoulder section, about half the length of the shoulder in fact.
The aftermath...I feel like I'm doing forensic photography.
These were eBay fasteners...I guess you get what you pay for. Here's a shot of a similar unit from Tracy, showing how the threads stop right at the shoulder instead of going way up into it to surprise the heck out of you just before lunch. I doubt that there's a specification for these, but it might be something to watch out for, especially if you're using a rare handle material or have a tight deadline to hold to.
Countersunk the 1/4" shoulder hole 3/16" inch or so, having already drilled the 3/16" shank through one scale, then the other during glue-up. Pretty standard stuff. This has been plenty of depth for the shoulder for hundreds of these fasteners previously. Well, as I'm grinding them off with a 50g Blaze, I see a little pucker showing up on one side of every single one. Six of them, two matching knives. I took a guess and poked the "pucker" with a drill bit and sure enough it was hollow underneath. Upon further investigation, and some very careful drill press action removing the remnants, I discovered that the internal thread of the female Corby goes nearly 1/4" up into the shoulder section, about half the length of the shoulder in fact.
The aftermath...I feel like I'm doing forensic photography.
These were eBay fasteners...I guess you get what you pay for. Here's a shot of a similar unit from Tracy, showing how the threads stop right at the shoulder instead of going way up into it to surprise the heck out of you just before lunch. I doubt that there's a specification for these, but it might be something to watch out for, especially if you're using a rare handle material or have a tight deadline to hold to.
