How To Choose A Mag Drill

How to choose the right mag drill for the job


Magnetic base drills, also known as mag drills or slugger drills, are used to drill heavy steel sections where a handheld drill would not suffice. The base of the drill features an electromagnet, that when energized, locks the base of the drill to the steel profile and allows the operator to apply a steady drill feed rate without dislodging or moving the base. These drills vary in size, weight and their horsepower, thereby affecting the hole diameter they can drill. They are mostly used in structural steel but are also used in applications such as drilling truck frame rails, steel signage, guard rails, etc.


Mag drills normally use annular cutters as opposed to solid drill bits. These are hollow cutters, so only the outer perimeter of the drill is in contact with the steel, thereby significantly reducing the horsepower needed to drill a given diameter.
Questions To Ask Yourself When Selecting A Mag DrillWhat is the maximum diameter hole that you need to make?

What is the depth of cut (D.O.C.) that you require? In other words; what is the thickness of the metal you need to drill?

Other Factors That Will Influence Your Selection:

  • Usage/production requirement – Some drills have similar capacities, but one may be intended for lighter work and the other for heavier duty use
  • Work Environment a lighter weight mag drill is preferred if you are working high up in the air, etc
  • Space Limitations – If you are working in tight spaces a low-profile mag drill may be ideal, such as: The Hougen HMD130 Mag Drill or the Fein JMC Magforce 90 Mag Drill.
  • Drilling Speed – most mag drills provide one drilling speed, but the heavier duty models are available with dual drilling speeds and in some cases, up to 4 speeds, such as the Jancy Max 4×4 Mag Drill.
  • Most mag drills are designed to use HSS annular cutters; operating speeds under 450 RPM. Carbide tipped annular cutters work best at speeds over 500 RPM (see How To Choose Annular Cutters)

Some dual speed mag drills are designed to use both; HSS and Carbide tipped annular cutters.

Types Of Mag Drills:

  • Manual Feed Mag Drills – the most common mag drills are manual feed. These require the operator to feed the cutter through the metal manually.
  • Auto Feed Mag Drills – These drills feed and return to the start position automatically, enabling the operator to press Start and run several automatic mag drills at one time!

The load sensing system in these auto-feed mag drills provides for faster cutting times; automatically adjusting the feed rate, and providing longer cutter life while eliminating the stress on motor due to improper operator pressure.

Other Special Application Magnetic Drills:

Mag Drill Accessories

The versatility of some mag drills may be expanded with the use of optional accessories, such as:

Twist Drill Adapter

Allowing the operator to use jobber drills from 1/2″ diameter and smaller with mag drills.

Countersink Kit

These kits allow the operator to quickly and easily counter sink for flat head bolts.

Tapping Attachment

As the name implies, this device is geared to tap steel. If your production requires tapping, make sure the mag drill you select will tap the size you need. Not all mag drills can reach up to 1-1/8; however, most can tap up to 3/4″.

Chain Mount

This accessory allows the operator to mount the mag drill on pipe and drill holes on center. The minimum pipe diameter is usually 3 & maximum is 12 ; larger sizes may be available based on the manufacturer.

Mag Drill Vac Pads

Allows the mag drill to be attached to non-ferrous metals with the use of shop air.

Cutting Lubricant For Mag Drills

The use of cutting fluid or cutting paste will extend the life of the annular cutter.



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