L70mm Drilling Tools Countersink Drill Bits Through Hole For CNC Cutting Machines

Drilling through holes on a CNC machine, in either spindle direction? This step through hole drill bit covers 4 mm and 5 mm blade diameters, 8 mm and 10 mm blade lengths, step diameters of 10 mm and 30 mm, a 70 mm overall length and a 10 mm shank, with right and left rotation both listed. One bit works shallow and deep holes via the step, chips clear as it cuts, and both diameters share the same collet. Price on request.

A shop drilling through holes on a CNC machine runs into the same three things: a bit that suits only one spindle direction, a change of bit every time the hole gets deeper, and chips that pack the hole and cook the edge. This step through hole drill bit is listed against all three.

It is a step through-hole drill bit for CNC cutting machines, supplied in right and left rotation. Blade diameter is 4 mm or 5 mm, blade length is 8 mm or 10 mm, and the two step diameters listed are 10 mm and 30 mm. The type on the sheet is step through-hole.

Overall length is 70 mm and the shank is 10 mm, so the same collet holds the 4 mm bit and the 5 mm bit. The step design is what lets one bit cover shallow and deep holes on the same setup instead of stopping to swap tooling mid-panel.

Chip removal is designed into the bit: swarf leaves the hole rather than packing around the blade, and packed chips are where heat builds and a through hole starts to burn. All sizes are listed for CNC cutting machines, and the 70 mm body clears the spindle nose on a nested panel. Price is on request.

What is on the sheet, and what each line changes at the spindle:

• Right and left rotation. Both handings are listed, so a bit matches the spindle instead of being kept aside for one head.
• Two blade diameters. 4 mm and 5 mm, the two through-hole sizes this series is listed in.
• Two blade lengths. 8 mm and 10 mm of blade length, so the depth range starts at the tool.
• Step diameters 10 mm and 30 mm. 10 mm and 30 mm are the two step sizes on the parameter sheet.
• 70 mm overall length. 70 mm from tip to shank end is the number to check against spindle nose clearance.
• 10 mm shank. 10 mm on both blade diameters, so one collet size covers the pair.
• Step design, shallow to deep. The step is what lets one bit work across a range of hole depths.
• Chip removal built in. The bit is arranged to clear chips, and clogging plus heat build-up is what stops a drill mid-hole.
• Step through-hole type. Specified for holes that break through the panel, not for pilot drilling.
• For CNC cutting machines. Listed for CNC cutting machines, which is the tooling these sizes are built to run in.

The usual answer is one bit per diameter, one per depth, and a separate one kept back for a left-hand spindle. What this bit changes:

• One collet, two diameters. 4 mm and 5 mm blades both run a 10 mm shank, so a size change is a swap and not a re-tool.
• Left-hand spindles are not excluded. Right and left rotation are both listed, so both heads can carry the same part number.
• Depth stops being a tooling decision. The step covers shallow and deep holes, so one setting serves both ends of the range instead of a second bit.
• Chips leave, heat does not build. Chip removal is designed into the bit, and heat at the contact point is what shortens edge life first.
• 70 mm of reach. 70 mm overall on a 10 mm shank keeps the spindle nose clear of the panel.
• Two blade lengths for panel thickness. 8 mm and 10 mm of blade length, so thin and thick panel work come off the same series.
• One sheet to order from. 4 mm and 5 mm diameters with 8 mm and 10 mm lengths are all listed together, so the size is picked in one place.
• Through holes, not pilot holes. The type is step through-hole, so the bit is specified for holes that break out of the panel.

Two blade diameters: 4 mm and 5 mm. Blade length is 8 mm or 10 mm, the step diameters listed are 10 mm and 30 mm, and every size runs a 70 mm overall length on a 10 mm shank.

Yes, if your collet takes a 10 mm shank. Both blade diameters share that shank, and the sizes are listed for CNC cutting machines.

No. Right and left rotation are both listed on this bit, so a left-hand head is covered by the same sheet as a right-hand one.

8 mm or 10 mm of blade length, on a 70 mm overall body. The step design is what lets the same bit cover shallow and deep holes rather than one bit per depth.

It lets one bit cover a range of depths. The bit is specified as step through-hole with step diameters of 10 mm and 30 mm, so shallow and deep holes come off the same tool.

No. Both run a 10 mm shank, so one collet holds either blade diameter and a size change stays a one-item swap.

The bit is shaped to clear them as it cuts. Chip removal is designed into the tool, and that is what keeps clogging and heat build-up from stopping the cut mid-hole.

Price is on request. Send the blade diameter (4 mm or 5 mm), the blade length (8 mm or 10 mm) and right or left rotation, and the quote comes back against those three lines.