While the fix is relatively easy if you have the tools and inclination to do it, it is not something that the end user should ever need to do.
Please Spyderco, fix this issue.
Linked below is the post on how to fix the detent and what use. Thanks to Shunsui and others for the fix & write up.
shunsui wrote: ↑Fri Dec 14, 2018 3:51 amI posted earlier that my Amalgam shook open rather easily. I ordered a KYOCERA 1635-0625.094 Ball Nose End Mill to modify the detent hole.
https://www.amazon.com/KYOCERA-1635-062 ... B01MSM7KDD
First of all BIG thanks to M0DiFiEDZ for his classic video on all this detent mod stuff.
https://youtu.be/S5H96riLLS4
Also BIG thanks to Nick Shabazz for his video on the Amalagam:
How to disassemble and maintain the Spyderco Amalgam Pocketknife
https://youtu.be/nwqccMaeNpU
This is the stuff you need to do the job.
You can do the job with just hand force. No need for a drill or dremel tool.
I used a plain tap & die set collet to hold the KYOCERA 1635-0625.094
You'll need a T8 torx driver. I'd get a Wiha if I were you.
The Triplet 10x is an eye loupe to get a better look at your work.
The blue and white thing is just a carved up toothbrush handle I use for a sturdy pry bar.
I never even taped up the blade, but you might want to.
When you take the knife apart, you'll notice the detent hole is drilled all the way through the blade. This is handy because you can practice on the side that's not used for the detent and get a feel for the cutting tool.
Work slowly, cutting just a bit at a time, and reassemble the knife to test the detent as you go.
I tested the detent strength with a trigger pull gauge.
My original detent was between 7-11 oz. You could shake it open with one shake.
I did three grinds on the detent hole progressively increasing the detent strength:
15 oz
1 lb 7 oz
2 lb 4 oz
At 2 lbs 4 oz, the visible detent ball was about 80-90% in the hole. I didn't want to take it any further as I wanted the ball supporting the lock bar, rather than the bar flat on the blade.
Note that what I've done is enlarge the very top of the detent hole with a larger ball shaped cutting tool. The result is a bevel or cup at the top of the hole for the detent ball to nestle down in.
Keep in mind that everything here is rather small. Doesn't take much cutting to do the job.
I came close to overshooting where I wanted to be. Go slow.
This is the result
The Amalgam is a sweet knife. I wouldn't have gone to all this trouble if it wasn't worth it.
Mine cut better than any knife I've gotten out of the box. Wasn't going to send that back.
The added bonus is now I can modify my other ball detent knives more to my liking.