Question about screw sizes and drill bits

Bob Warner

Bob Warner

KNIFE MAKER
OK guys, I have been reading and looking through a lot of charts on the web. I am having a bit of trouble with screw/drill sizing.

Is there a chart that anyone knows of that will give me the following information for the most commonly used folder screws?

For example: If I want to use a 0-80 screw what drill do I use to drill the hole that needs to be threaded? I know TI uses a different size than steel so both drill sizes are needed.

I also need to know what drill size for the clearance hole so the screw can pass through.

Then I need the drill size for the head of the screw to be able to recess it into the handle material. Since there are several head styles, this could be confusing the issue a bit.

I am hoping someone has a source for this or has already compiled the information, basically because I am pretty busy right now working on welding jobs (and need all I can get) and don't have a lot of time to search the web for the information.

If this has been figured out by anyone and they can post a chart or just a list of the info, I would GREATLY appreciate it.

If nobody has this but has some of the information, please post it and we can create a chart with the combined knowledge.

I looked long and hard at all the forums I know of and have not found this.

Thanks,

Bob
 
Bob,
I only use 1-72's & I use a 1/16" bit for the hole to be threaded & ream the hole that is not to be threaded with a # 49 . I countersink the button head screws with as 9/64" & flathead screws with a 1/4" spade bit . Hope that helps . Joe
 
I use a lot of 2-56

I thread form my taps and use a .078 drill for the threaded holes and a #44 for the clearance. Counter bore with a #19 most of the time.
 
Here's a little chart I made for my shop....

ScrewDrillchart.jpg



I tried using 0-80 screws a few times, but found that they are so tiny that I often twisted the heads right off of them....creating more problems for me than they were worth. 2-56 screws are by far my most used size. I even use 2-56 for the interior screws on my folders. A little tip here....go to Smallparts.com and look at their selection of 2-56 82 degree screws. I have been using their 2-56 slotted and Phillips head screws for my interior screws for several years now. They are WAY less expensive, and I can see no difference between them and screws costing 3-4X as much.
 
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use forming taps in Ti you will end up with far better and stronger threads I spent years tapping m5 and m10 in 6/4 Ti

use a tapping head or hand tapper set up unless you area robot never go free hand tapping Ti.
 
I use 0-80 screws on my folders with torx drivers. For tap drill size I use 3/64 (.0469) dia. options are 1.2mm (.0472) or 1.25 mm (.0492). For screw clearance use 1/16 (.062) or for tight fit #53 (.059). Make sure that the hole is burr free, use a spiral point tap and a good tap lubricant. I use a low powered hand held screw driver to tap my Ti. Dan
 
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Bob,
Do you have the Machinery's Handbook? It has a table in that gives guidelines for cutting threads. The table also takes into consideration the % thread and material thickness.

This company has a very good assortment of screws and fasteners, many in stainless steel. I like them because you don't have to buy them by the 100's. Olanders

Ric
 
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