Where to get long series centre drills

[Tiggy_dorset]

If you're using 'em in a drill press what about spotting drills http://www.guhring.com/documents/catalog/drills/ncspotdrills.pdf?

Spot drills are on my list.
Im drilling strips of 1mm mild steel. Unless I go through on the first pass with a spot, the beauty of the centre drill I have at the moment is using it to pilot, before stepping up, one less tool change.

 

[Spark plug]

Or if your only drilling sheet then you could buy the larger drills in stub length, and an added bounus they flex less than standard length drills.

 

[hotrodder]

Spot drills are on my list.
Im drilling strips of 1mm mild steel. Unless I go through on the first pass with a spot, the beauty of the centre drill I have at the moment is using it to pilot, before stepping up, one less tool change.

How big is the final hole and how wide is the strip? Step drills typically produce more accurate/rounder holes in sheet metal than twist drills, are stiff and assuming the final size is something common would be zero tool changes. Punching them would be even faster, obviously fairly limited with regards to hole dia and throat depth but a Roper Whitney hand punch is my go to tool for making holes in anything within it's capacity

 

[Tiggy_dorset]

Or if your only drilling sheet then you could buy the larger drills in stub length, and an added bounus they flex less than standard length drills.

Another good suggestion, Could alwas be handy anyway having a set of stubbies to hand. I'll do a search and add a set to the ever growing list.

 

[Tiggy_dorset]

How big is the final hole and how wide is the strip? Step drills typically produce more accurate/rounder holes in sheet metal than twist drills, are stiff and assuming the final size is something common would be zero tool changes. Punching them would be even faster, obviously fairly limited with regards to hole dia and throat depth but a Roper Whitney hand punch is my go to tool for making holes in anything within it's capacity

I lied when I said I'm drilling 1mm, its actually 2 layers of 1mm. Making some clips and brackets of various shapes and sizes. Some need the holes to be lined up (as pic below). Some don't need holes aligned which get subbed out to be pre cut to size and punched. However the ones needing lined up I have to drill after bending, as you cannot guarantee the holes be be precisely aligned after bending.
Most clips are 16mm wide, with holes ranging from 6mm up to 10.5mm

 

[optima21]

I found these "lengthen" centre drills on ebay while looking for something else. Im guessing they might not be dormer quality though

http://www.ebay.co.uk/itm/271649341284

 

[Tiggy_dorset]

the original set I bought cost me about £15 for 4 sizes. They blunted pretty quick before a few of the tips snapped. I have since bought one single one for ~£15 from Cromwell, and doing the same jobs it has held up well so far. I would expect the ebay one you listed would be on par with the cheaper ones, but hey its from China, you never actually know what you are gonna get lol.