Column Drilling Machines

Column drilling machine: the workhorse of the shop

A column drill stands on the floor: the column carries the drilling head and a table that is raised or lowered to suit the part. Compared with a bench drill it has a greater throat depth, 225–325 mm, and a 100–200 mm spindle stroke, drills larger holes and taps threads.

The catalog carries MAXION machines from Ø18 to Ø50 mm. The MAXION UNIMAX 2 and MAXION UNIMAX 2 T drill up to Ø18 mm and tap M12; the MAXION BTB 20 drills Ø20 mm; the MAXION UNIMAX 3, MAXION UNIMAX 3 T and MAXION UNIMAX 3 AV drill Ø25 mm and tap M20, with a 30–400 mm/min power feed on the AV. The MAXION BT 36 and MAXION BS 36 drill Ø35 mm, with an MT 4 taper, 4 kW, a 15–400 mm/min power feed and M30 threads. The MAXION UNIMAX 4 Basic+ drills Ø35 mm, and the MAXION UNIMAX 4 Ø40 mm, with 7.5 kW, M36 threads and programmable cycles. The largest is the MAXION BS 50 AVST: Ø50 mm, a 200 mm spindle stroke, M45 threads and four fixed feeds. The MAXION H 25 AV has a horizontal spindle: Ø25 mm, M5–M16 threads up to 100 mm deep, and a 30–400 mm/min power feed.

For small holes up to Ø20 mm a bench drill is enough; for large parts and holes far from the edge, a radial drill. Batches of threads are cut on tapping machines. The UNIMAX 3 is prepared for a milling kit, but for regular milling choose a drilling-milling machine. General selection criteria are on the drilling machines.

If a column machine is being chosen to replace a Soviet one, the match is almost literal: the 2N135 drills 35 mm, has a 300 mm throat, a Morse 4 taper and 4 kW — exactly the figures of the MAXION BT 36, so the tooling moves across without adapters. The breakdown for the 2M112, 2N135 and 2A135 is in the article on replacing a Soviet drilling machine.