100 degree vs 90 degree csk screws
100 degree vs 90 degree csk screws
(OP)
I'm using a Jonathan slide which has a 0.199 hole csk 100 degree x 0.395. I am attaching this slide to a unit with M4-10 screws that I can only find with 90 degree csk... is the difference in bearing angle enough to be concerned about? Is there a source for metric hardware with 100 degree csk? Thanks.





RE: 100 degree vs 90 degree csk screws
The .199" diameter is the exact sharp diamter of a #3 machine screw flat head 100 degrees. I do not understand your .395" number, unless perhaps that is the diameter. The sharp diameter of a #10 flat head screw is .385". A .395" countersink would sit your screw below flush. I am assuming you are using inches.
A #3 screw has a major diameter of .099", and they are hard to find. There are small solenoids on the market that use 3-48UNC tapped holes, and I am wondering what drugs the designers were on.
A 100 degree countersink definitely is English. Metric flat head screws are 90_degree. Most English screws are 82_degrees. Hopefully, a #10 screw will work for you.
I do not know the consequences of putting a 90_degree countersink screw into a 100_degree hole. It would look absolutely unprofessional.
JHG
RE: 100 degree vs 90 degree csk screws
You have a .199" diameter hole with a .395 diameter x 100 degree countersink. This is a hole for a #10 100 degree flat head screw.
Be careful not to get the more common 82 degree screws.
JHG
RE: 100 degree vs 90 degree csk screws
RE: 100 degree vs 90 degree csk screws
Force stays the same, area is reduced, thus tensil stress introduced into the screwhead increases inverley porportional to the decrease in area. If you sketch it out... eventually the head will **POP***.
Wes C.
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RE: 100 degree vs 90 degree csk screws