Self Tapping Screws Don't Self Tap
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Self Tapping Screws Don't Self Tap
Hi,
For woodworking I bought a Trend 50 inch Varijig straight edge clamp guide also a Trend VJS/CG/SQA VJS/CG squaring attachment to fit on the end of it. The squaring attachment comes with two self tapping screws I've tried, quite forcefully but the screws aren't interested in self tapping. The only thing I can think off is use a very narrow drill bit to drill a mm or so down to get them started.I have a floor standing drill press but not any tiny drill bits
I don't want to bodge the fit, as defeats the object of the squaring attachment holding the clamp square on the workpiece.
For woodworking I bought a Trend 50 inch Varijig straight edge clamp guide also a Trend VJS/CG/SQA VJS/CG squaring attachment to fit on the end of it. The squaring attachment comes with two self tapping screws I've tried, quite forcefully but the screws aren't interested in self tapping. The only thing I can think off is use a very narrow drill bit to drill a mm or so down to get them started.I have a floor standing drill press but not any tiny drill bits
I don't want to bodge the fit, as defeats the object of the squaring attachment holding the clamp square on the workpiece.
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Re: Self Tapping Screws Don't Self Tap
There are various types of self tappers. Some cut a thread. Some form a thread. Anf then there are sheet metal screws. A photo of the screw would help.
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Re: Self Tapping Screws Don't Self Tap
Hi Thanks,
I've tried taking several close up photos of the screw. Unfortunately the camera macro feature doesn't seem to work too well.I hope you can make out the type of screw?
Cheers.
I've tried taking several close up photos of the screw. Unfortunately the camera macro feature doesn't seem to work too well.I hope you can make out the type of screw?
Cheers.
Re: Self Tapping Screws Don't Self Tap
That looks like a self-drilling screw for use in metal (probably other uses too). It won't harm anything if you drill a pilot hole that is less than the diameter of the screw's "drill".
Sometimes these things require a lot of downward force to get them to "start". The fact that it is a pan head and not a hex head makes that difficult.
Sometimes these things require a lot of downward force to get them to "start". The fact that it is a pan head and not a hex head makes that difficult.
Re: Self Tapping Screws Don't Self Tap
I always drill pilot holes just smaller than the minor diameter for such screws.
'Makes a world of difference!
~RN
'Makes a world of difference!
~RN
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Re: Self Tapping Screws Don't Self Tap
OK thanks people.
Re: Self Tapping Screws Don't Self Tap
The other thing is such screws respond far better to being installed by power than by hand. If the screw head accommodates a Phillips driver, they're pretty easy to install, especially with power. Slotted heads tend to be troublesome unless you have the proper driver, which keeps the blade in the slot. And, as stated, I tend to drill a pilot hole that is barely undersized, thus allowing the screw to determine the desired hole size. Drilling the hole with the screw without a pilot hole can be frustrating.
Wise people talk because they have something to say. Fools talk because they have to say something.
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Re: Self Tapping Screws Don't Self Tap
I sometimes start those screws with a hammer. I wouldn't do so in this case, though. Better to drill a pilot hole. It need not be full depth.
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Re: Self Tapping Screws Don't Self Tap
OK thanks.
Re: Self Tapping Screws Don't Self Tap
Another solution would be to thread the holes with a tap, and use some quality machine screws.
BC
If there was only one way to do each machining job, the smell of sulphurized cutting oil smoke would have fewer fond memories.
If there was only one way to do each machining job, the smell of sulphurized cutting oil smoke would have fewer fond memories.