Want to counter sink some screws in 2mm thick aluminium flat pieces, will be fixing the ali with 4 gauge screws, will the screwfix HSS 12mm counter sink bit be o.k or is it to big ? many thanks
It's fine. Just take it slowly, and check regularly with a screw as you progress, until it reaches the correct depth. With such thin sheet, if you go too fast, you could end up with a huge hole instead of a countersink. Before you start, have you checked the depth of the countersunk part of the screw to make sure that it can be accommodated within a 2mm thick sheet. BB
Yes,it will be OK but the Ruko ones give a smoother finish but the smallest they will do is a 3.0mm hole as the tip is 2.5mm . Use a slow speed when countersinking, and a bit of parafin is a good cutting fluid for ali. Jason
Use a 6 or 7mm HSS drill-bit and you will make the clearance hole less big than you will will a countersinker, normally. Tad more care needed not to go right through. Mr. HandyAndy - really
Yeah that will be cracking on 2mm ally.... as soon as its bit you through and ****** Some of you really do need to get a bit more experience. Mr. HandyAndy - really
Handy-andy you daft knob, im sick of your idiotic comments, Hitch is clearly correct. A drill bit is not a countersink. This poster wants to do the job properly not a bodge like you recommend. Passy - Really
Yeah that will be cracking on 2mm ally.... as soon as its bit you through and ****** Some of you really do need to get a bit more experience. Mr. HandyAndy - really Handy - I think you need to buy some new HSS drills - yours are obviously blunt.
Handy-Andy you complete fool, Hitch knows what hes doing, yes i am aware he spent one year as a sheet metal worker and 80% of the work was ally you ****! Now, **** back off to B&Q at your own pace. Passy
You idiots. If you don't know how to control a drill and a drill-bit, you shouldn't be touching the stuff. In all my living years I have NEVER used a countersink on metal. I have ALWAYS used a HSS drill-bit of the appropriate size. As I said before, it makes the clearance hole smaller because of the lesser angle on the drill-bit. There is need of more control but a little practise(you don't push the drill with your foot to get the most pressure), piece ofpis. More practise, boys. Mr. HandyAndy - really
A countersink countersinks. A drill-bit countersinks. What's not correct ? A pencil sharpener sharpens pencils. A stanley knife sharpens pencils. What's not correct ? Which one do you use. A stanley is not the correct tool. Mr. HandyAndy - really
Handy - at the start of this thread 3 different posters gave what to me seemed very reasonable advice. I don't know the skills of the original poster but he seems to have some idea what to do and was asking a sensible question in the circumstances. Your post about using a 6-7mm drill seems to be a retrograde step when the OP was already talking about buying a countersink.
A countersink countersinks. A drill-bit countersinks. What's not correct ? Using a countersink to drill holes with...and vice versa A pencil sharpener sharpens pencils. A stanley knife sharpens pencils. What's not correct ? Which one do you use. A stanley is not the correct tool. Mr. HandyAndy - really You obviously don't own any carpenter's pencils which says it all really. Goodnight.
It's fine for people to recommend the use of a countersink. What I'm saying is that the job can be done equally as well, if not better in some cases, using an ordinary drill-bit that dvddvd may already have in his toolbox. I would challenge anyone here to make a better job with a countersink than I would with a drill-bit. The ONLY differences in the drill-bit method are that you have to exercise a bit of restraint not to drill through, AND the clearance hole will not be made as big as it would with a countersink(which is more than likely a benefit). Mr. HandyAndy - really
Handy, do you re-grind your drill bits to suit the csk angle of machine screws? the head will not sit correctly in the "flatter hole" produced by a twist drill and will leave a gap around the edge. This can affect the pull out strength of the fixing as well as looking unsightly. Jason (O level grade A - engineering theory & practice and 20 odd years Model engineering experience)
Handy, do you re-grind your drill bits to suit the csk angle of machine screws? the head will not sit correctly in the "flatter hole" produced by a twist drill and will leave a gap around the edge. This can affect the pull out strength of the fixing as well as looking unsightly. Jason (O level grade A - engineering theory & practice and 20 odd years Model engineering experience) As a matter of fact, I do. Mainly with wood bits though, as I find they drill better with slightly more angle. But for machine screws, I have always found that the countersink on them is at slightly less of an angle than woodscrews, so a drill-bit does work quite well with them. The main reason I use drill bits is because a countersink is not easily sharpened, but a drill bit can be sharpened until there is only shaft left, so economy and convenience really. You are correct in pointing out the angle though, but I must admit that the problem has never really arisen for me, as I have found that on tightening the screws the angle difference disappears. I do concede that it is not the perfect solution, but it's always worked for me. Mr. HandyAndy - really
A few basic rules, 1) The counter sink angle is totaly different to that of a drill. 2) To get a neat cut the counter sink MUST be have an odd number of cutting faces. Same goes for reamers. Otherwise you don't get a round sink. 3) A drill should be ground at the correct angle for optimum cutting but, A drill should not break through the other side until it is cutting its full diameter. Where this is not possible you should counter drill first. Thats the facts, not gonna get drawn into being ****** though.