For some reason, I can't find this information (and if it's somewhere really obvious, my apologies). I have to secure a handrail into a plastic-covered steel doorframe, and thought to use 6x25mm pan head self-tapping screws. But what is the correct size for the preliminary hole?
Many thanks.
In article , Bert Coules writes
Yep, really obvious :-D
Searching for "drill size" "self tapping" screw gets a few:
Presto better as it gives holes vs thickness.
Fred,
Agreed! Sorry about that: I've no idea why it eluded me. Thanks for the links.
3mm it is, then.In article , Bert Coules writes
No worries, googledar fails us all at one time or another ;-)
Btw, don't know if anyone else has noticed but google search has definitely dumbed down recently, I search for X, Y, Z and get hits for X, Yish and without Z at all, v frustrating. These days I have to apply quotes to terms that I definitely want to appear to get anything sensible.
The thing that really annoys me about Google UK is that damned predictive list which generates itself below the search box as you type. The ostensible ways of turning it off don't seem to work.
In article , Bert Coules writes
If you turn off javascript it wont do that but then you have the problem of navigating to search results that require it and changing settings. With Opera though, you can change settings like that very quickly using F12 to bring up a little pop up list controlling those settings.
Google can be very dumb.
Especially the adverts that extract your search string
eg search for "square swiss rolls"** and you get "Buy square swiss rolls on ebay now"
**Or anything equally stupid!Bob
The effects of doing that might well be the lesser of the two evils. Thanks for the thought.
Bert
I generally read the diameter of the screw root with callipers to get the correct size clearance hole. Generally speaking it is usually 1/2 the metric size which for me usually means 2.5 to 4.00 mm drill bit.
Don't jump up and down if you're a precision engineer with a need for exacting tolerances. This is just a general hint
Paul Mc Cann
Paul,
And is appreciated as such. Going by my resolutely low-tech method of holding up drill bits against the screws and comparing them by eye, 3mm does look fractionally smaller than the diameter at the bottom of the threads: left to my own judgement I would probably have gone for 3.5mm or even 4mm. I'll probably have those bits to hand when I do the job, just in case a 3mm hole does prove to need more effort than I think the screws can take.
Bert
Well, 3mm holes worked a treat, and though the thickness of the material I was screwing into proved a lot thinner than I was expecting, everything seems to be nicely secure. Thanks for all the advice.
Bert
Tried ? Works here...
Thomas Prufer
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.