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- May 30, 2011
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While designing an engine in Autodesk Inventor, I looked through the machine screws that they had models for.
Looking for screw sizes, a 1/4" screw would be too large, so I opted for a 1/8" screw which is a #5-40. Going to hardware stores I see they have #8, #6, and #4, completely skipping over #5. Why aren't #5 machine screws used as much? They seem like they'd be the standard over #4 or #6 due to it being an EXACT outer dimension of 1/8".
The diam of a #4 screw is about 0.112", and #6 screw is 0.1380". What makes these odd sizes BETTER than an exact 0.125" screw?
Able to pick up some online at http://www.microfasteners.com/catalog/products/SSCSCA.cfm or http://www.fastener-express.com/socket-head-cap-screws-alloy-steel.aspx, way better prices than Fastenal
Ian
Looking for screw sizes, a 1/4" screw would be too large, so I opted for a 1/8" screw which is a #5-40. Going to hardware stores I see they have #8, #6, and #4, completely skipping over #5. Why aren't #5 machine screws used as much? They seem like they'd be the standard over #4 or #6 due to it being an EXACT outer dimension of 1/8".
The diam of a #4 screw is about 0.112", and #6 screw is 0.1380". What makes these odd sizes BETTER than an exact 0.125" screw?
Able to pick up some online at http://www.microfasteners.com/catalog/products/SSCSCA.cfm or http://www.fastener-express.com/socket-head-cap-screws-alloy-steel.aspx, way better prices than Fastenal
Ian