Step Drill Bit, Audel HSS Double Slot Cone Cutting Drill (5mm-35mm) with Titanium Coating for Wood, Stainless Steel, Sheet Metal -Silver

Buen precio. Funciona bien, pero hay que tener calma con metales gruesos.

Fair enough.

herramienta duradera con un acero excelente

Needed to drill 32 mm holes in sheet aluminium, prices from other suppliers were more than double this one, ranging up to around £50. Checked out the diameters of each hole size, they varied from 0.1 mm to 0.13 mm under size but when the amount of vibration that a drill of this type produces is taken into account the end result is quite close to the specified size. I checked the state of the cutting edges before using it, in pictures 1-3 the V shape shows slight burrs and knocks due to the grinding process and presumably rough handling before packing. I was able to clean these up quite easily with a few strokes of diamond stone, the cleaned up results shown in pics 3-6. These were taken after using the drill. At this price it is not reasonable to expect the finished quality that you would get with one costing around £50. At this price I was satisfied with the end results, and for low volume usage this would be ideal with a good range of sizes available. In use I did not make a pilot hole, just center punched it, went through easily although the metal did warm up a bit, just remember to stop at the correct step! No lubrication was used this time, next time will try it with some WD40 and see what difference there is. For DIY usage this is good value and I give it 4 stars.

For the price this is bloody fantastic. So far I have used it to enlarge a hole in a plastic dashboard panel to 27mm and also to enlarge the mounting holes for a safe from 8 to 12mm.Plastic capable - Check3mm steel panel capable - CheckThe cutter shows no sign of wear after either task. The hole it made was nice and clean in the plastic, metal may need some deburring afterwards as the cutter can leave some swarf attached to the workpiece.There is not a lot of tolerance between the steps so this tool will not be any use for thick materials. Anything more than 3mm will require drilling from both sides to obtain an even aperture or you'll end up with a cone shaped hole.You’ll need at least a 1/2” chuck on your drill to fit this bad boy in, the shank is chunky.Take the job nice and slow to avoid snagging or over drilling the hole too big. Remember, you can’t drill a bit back on.

As others have written you do get what you pay for in general. I'm normally a 4-or-5 star person, or 1. This is not terrible however it came pretty blunt ( I'd expect razor-sharp from the factory ). I'm assuming that the sharpness is a bit of pot-luck as some folk seem to have had a better experience than me. Also, the steps are a bit short so going through a fairly thin piece of mild steel I was already nudging the next size before the hole was through.Saving grace for the sharpness is that the flutes are straight, so you can get a stone or similar on the 2 edges; I did that and I now have a reasonable cutter at, let's face it, a very reasonable price.

I purchased a water butt and the connector hole was 27mm. I could not find a single drill piece of that radius so both this multi-sized drill piece. It worked fantastic. To make sure I did not make the hole too big by missing the actual mark on the drill of 27 I used tipped at age correct dimension and low and behold it showed up as I drilled and a perfect circular hole was made.

I used it 15 times on a plastic panel, then was to do the same on steel panel, 2.5 mm thick, went blunt after 4 uses.Not suitable fir steel sheet which what I thought it said it could deal with