Professional Power Tools – The Complete Guide to Mag Drills
The mag drill can bring the clean, convenient performance of a stationary drill press to any point on a construction site. Utilizing a strong electromagnetic base, it can be adhered tight to carbon steel surfaces, even upside down or vertically, then used to drill holes of up to 5-1/8″ (130mm) diameter and tap holes of up to 1-5/8″ (40mm) diameter.
It’s as portable as a handheld yet as stable as a drill press, ensuring precision accuracy and faster performance. If the surface cannot come to you, a mag drill can come to the surface. Unsurprisingly, they’re utilized across a diverse range of industries, from shipbuilding to steel fabrication, and you’ll spy them being used on construction sites across the country.
Able to work across multiple surfaces regardless of remote positions and problematic orientations, mag drills are an increasingly popular part of the tradesperson’s arsenal, and one that you cannot afford to ignore. If the thought of researching these tools independently doesn’t appeal, all you need to do is read this exhaustive guide.
Information is broken down to help you grasp key concepts quickly and easily, but you’ll still end this post having developed a thorough understanding of:
1. The Anatomy of the Mag Drill
The best way to understand how a mag drill works is by taking a look at how its independent components work together. Here’s your anatomy of the mag drill.
- Most mag drills use a brush DC motor. Grease gearbox motors work best for frequent heavy use when you need to lower your costs. Oil bath gearbox motors are a little more expensive but can significantly increase motor life.
- The arbor attaches to the drill, offering manual or quick-changing configuration with the annular cutter.
- Front support brackets form a connection point between cutter and arbor, plus a boundary to prevent the operator from drilling too deep.
- The annular cutter, a hollow, multiple cutting edge tool with various groove options, is used to drill holes into your chosen material.
- The pilot light directs a focused beam of light just below the annular cutter to improve visibility and hole location accuracy.
- The electromagnet fastens itself to the steel surface you need to work with at the touch of a button.
- The housing provides protection for internal components and a solid grasp for the operator.
- Feed handles are turned to move the cutter upwards and downwards.
- The sliding section moves smoothly along the gibs.
As versatile in terms of power selection as they are when it comes to working with challenging surfaces, mag drills are available with electrical, pneumatic, or hydraulic power. Each one holds its own pros and cons.
- Electrical: Dependable, lightweight, powerful, and compact, electric mag drills are popular enough to offer numerous different sizes, as well as optional reversible motors. That said, they are unsuitable for use in wet environments.
- Pneumatic: Using compressed air instead of electricity removes the hazards associated with operating in wet environments. Pneumatic mag drills are also ideal when working closely with flammable and/or combustible materials, though they are more expensive to buy and run.
- Hydraulic: Hydraulic mag drills use a closed loop power system that won’t be penetrated by water. As such, they are typically used underwater. A niche product for a niche field.
2. Types of Mag Drills
Every mag drill utilizes the same basic anatomy detailed above, but a surprisingly diverse lineup of separate types is available to fit around any job, whether you need to crawl into a cramped area or climb up to a high point. Common mag drill varieties include:
Lightweight Magnetic Drilling Machine: For those who need to ascend towers or other high points, keeping weight to a minimum is crucial. Lightweight mag drills typically fall in the 9kg to 12kg range, with power outputs up to around 800 watts. They are meant for drilling only, not tapping. Many newer lightweight machines are variable-speed, quill-feed models.
Magnetic Drilling Cum Tapping Machine: Tapping creates a groove along the side of the hole to accommodate screws and other fasteners. With a reversible motor fitted, mag drills can also be used for tapping.
Magnetic Drilling Machine with Swivel Base: The capability to rotate to left or right assists the operator when multiple holes need to be made alongside each other without demagnetization. This is particularly useful when drilling on a horizontal or overhead plane; with the swivel base, you can adjust the drill’s position without having to hold its full weight.
Compact Horizontal Magnetic Drilling Machine: Portability is a central advantage of the mag drill, and compact models allow users to take them into confined areas. Motors are powerful, and most compact machines will be equipped with strong LED lights in addition to the main pilot light.
Automatic Magnetic Drilling Machine: An increasingly popular option, automatic mag drills take the feed automatically, meaning that operators don’t require a high level of skill. The life of the tool is commonly increased since operation will be steady, and you’ll benefit from being able to make multiple holes at once. Modern safety features, such as overheat and overload protection, help explain the recent rise in use.
Cordless Magnetic Drilling Machine: Another step forward is the cordless mag drill. Advanced lithium-ion batteries are charged internally or externally, increasing the convenience of drilling in remote or hard-to-reach locations. As a general rule of thumb, expect to make around 40 holes per charge.
3. Types of Drill Bits
The design of your mag drill is important, but it’s the bit itself that is going to make your cuts and bore your holes. As before, a refreshingly full range of options is available to help accommodate a far-reaching set of requirements, with common drill bit types including:
Solid Drill Bit: The solid drill bit provides dependable penetration when only a basic hole is required, and you’ll find them in numerous sizes and materials.
Raptor Cutter Short and Long Series:Utilizing unique geometry, these are some of the hardest wearing drill bits available, with up to a 50mm cutting capacity. Expect an average 35.5% less wear and 16.4% faster drilling time over 200 holes compared to the closest competitors.
Pilot Drills: Thinner bits create a small initial hole in the material to help guide a larger drill bit inside and make room for other hole making tools.
TCT Cutters & Pins: Tungsten carbide tipped pins are able to eject the slug from the center of the cutter after the completion of each hole.
Alfra HSS Reamer: A double-use reamer perfect for enlarging and aligning holes in steel fabrications. Unique geometry is used to create a specially designed cut.
Powerbor 3/5: The PowerBor line covers a wide variety of bits, and their innovative construction allows for multiple hole sizes using just one machine.
Countersinks: Keep the heads of bolts or screws flush with or just below the surface by using a countersink drill bit to cut a conical hole. They can also be used to remove the burr the remains after drilling or tapping, buff out any hazardous sharp edges, and generally improve the finish of the product.
Short Hand Drill TCT Holecutter: One of the newest drill bits currently available, the TCT holecutter allows for astonishingly fast hole boring, even with a portable drilling machine.
Impact Reamer Hexagon Shank: A pioneering reamer that uses an engineered hex shank. Useful for aligning or enlarging existing holes that are either overlapping or smaller than the required diameter.
Impact Reamer Weldon Shank: Fits into a standard Weldon magnet drill arbor – ideal for use with lightweight mag drills.
GoldMax Tungsten Carbide TCT Burrs: TCT burrs are made for flawless cutting, faultless control, and peace of mind over years to come.
4. Surfaces & Environments
A mag drill is able to hold itself firmly against metal surfaces, but the surface should be carefully inspected before you begin work to avert any serious problems or accidents. These are still heavy machines, and any slight flaw or lack of hold could prove hazardous to both drill and operator.
Firstly, take the time to check out the surface. It should be:
- Clean: Chips or other foreign items could rest beneath the magnet and radically decrease its holding power.
- Flat: The magnet’s holding power will be diminished over rougher surfaces.
- Without Rust or Paint: Rusting or paint, especially epoxy, will mean that the magnet cannot hold properly.
- Thick: Cutting material of 3/8″ or less should be avoided since holding power will diminish with thinner surfaces.
Environmental conditions should also be taken into account. If you’re working in an area containing lots of moisture, you should take care to keep the surfaces dry and use a machine that isn’t powered by electricity.
5. Operational Tips when using a Mag Drill
It’s remarkably easy for inexperienced operators to assume that working a mag drill will be a walk in the park. After all, the magnet holds the drill in place, so surely all that needs to be done is the motor turned on and the drill bit depressed.
In reality, these are complex machines that need to be handled with immense respect. Damage or injury can occur if the correct steps are not taken, and you may impair the effectiveness of your work and the condition of your machine if you perform incorrectly. Studying the following points is crucial.
Using the Control Panel: Before activating the machine, you need to become familiar with the dials, settings, and display of its control panel – especially important are the safety, magnet, and motor switches. The safety switch will be located at the base of the drill, and it will enable operation only when the drill is placed against a clean, flat surface. Should the system detect any lift, the motor will be turned off. The magnet switch energizes or de-energizes the base, and it works automatically with the safety switch. The motor switch starts and stops the motor, and it cannot be activated without the magnet switch on.
Chain Instructions: A chain should be used at all times to prevent tool damage and potential human injury in the event of a problem. A mag drill can come away from its surface for a variety of reasons, from power loss to surface problems. A chain acts as a vital insurance policy against such eventualities, so you shouldn’t risk working without one.
Safety Switch: When the safety switch light is green, the system is operating normally. If it is red, the drill may need to be serviced, or you may be working with an uneven or unclean surface. Before starting work, test the safety switch by placing the drill on a safe surface and then rocking it so the magnet lifts away from the surface – the light should turn from green to red.
Pilot Light Switch: The pilot light illuminates your working area. Check that the light is unblocked before you begin to work.
Operate the Mag Drill: After checking the surface and verifying that the safety switch works properly, place the drill by slowly feeding the arbor until the pilot point is just touching the center of the hole that needs to be drilled. Take the time to secure your drill using a safety chain, then activate the magnet switch. Turn the feed handle until the pilot is above the work surface, then make sure the area is free from clutter and hit the motor button. Don’t pressure down too hard unless you want to cause stress to the machine. When you’re done, eject the slug, turn off the magnet, and then disconnect your mag drill from its power source. You’ll need to remove any chips that have been made.
6. Mag Drill Maintenance
A mag drill is made to last reliably even through heavy use, but basic maintenance is still more than a good idea if you want to increase the life of your tool and minimize wear on its removable parts. You’ll find that operation is smoother and overall costs are lower if you commit to periodic cleaning, and all you need to do is:
- Tighten all fasteners on a regular basis.
- Check motor brushes and replace them when worn.
- Check for cracks and frays in the cables, returning to authorized repair center for replacement if any are seen.
- Treat slide dovetails, brass gibs, and the feed gear rack to grease.
- Remove the arbor and pack the front support bracket’s bearing with grease.
- Clean and re-lubricate the safety switch plunger.
- Remove the magnet and check behind it to ensure that the area is clean. Tighten all screws when the magnet is placed back in its normal position.
7. Must have accessories for your Mag Drill
The difference between a mag drill that needs to be replaced or repaired after just a few months and one that continues working dependably for years to come can come down to something as simple as the difference between investing in the proper mag drill accessory or focusing on short-term gains by skipping the necessary equipment.
While by no means exhaustive, the following selection of accessories are well worth considering.
Cutting Oil: Sprayed directly onto cutting surfaces, cutting oil can keep the workplace at a stable temperature while simultaneously providing additional lubrication for the working edge of your drill bit. You’ll also help prevent rusting and ensure that any toxins, bacteria, or fungi are not present on the surface.
Broaching Cutter Oil: Using broach lubrication will allow any chips to slide away from the drill bit easily, curving around the tooth gullets to ensure that frictional heat and wear is kept to an absolute minimum.
Coolant Unit: Though not strictly necessary, coolant units will be more than worth the money you pay for them. Spray coolant can work to some degree, and you’re certainly more than welcome to make use of it. However, dedicated coolant units provide superior protection compared to spraying the drill while it is spinning.
Aerosol Spray Lubricant: Spray lubricant becomes less necessary when you use a coolant unit, which you should. That said, aerosol-based coolants can be useful for low-powered machines or when dealing with areas that require a very light unit.
AeroPaste: A specially-made paste-type aerosol lubricant that is perfect for reducing wear and excess heat when broaching, tapping, reaming, or drilling. It’s a fantastic product to use with a mag drill since its high viscosity allows it to cling to surfaces rather than dripping down – you’ll be able to spray it against surfaces parallel with the ground without it coming away, which is ideal when the drill must be used upside down.
Pillar Drill: A traditional pillar drill can reduce your dependency on your mag drill, allowing it to be used in areas where portability and lightness are necessary.
Extension Arbor: Extend the reach of your drill bit by swapping your mag drill’s standard arbor with an extension model. It’s not always necessary, but it’s vital when you want to go deep.
8. Mag Drill Brands
The mag drill is not yet made by all drill manufacturers, but there are plenty of well-known names, plus a selection of smaller, more specialized companies, that can provide a solid range, including:
Metabo: A German company that makes a wide range of different drills, Metabo is one of the few brands that carries cordless models, making it the go-to choice if you need to work far away from dependable power sources.
G&J: A leading provider of specialist tools, G&J produce some of the most dependable mag drills on the market. The REVO Low Profile 35 is one such example. With its low profile and powerful motor, it was designed to be used for truck chassis work.
Hougen: Hougen probably offer buyers the most comprehensive selection of magnetic drills, and they remain an important source of industry information covering everything from proper safety and maintenance to basic walkthroughs.
Champion – Cutting Tool Corp: A leading company since its inception back in 1897, Champion can deliver several mag drills, despite the fact that they do not specialize in them.
DEWALT: The yellow and black design of DEWALT is seen on construction sites all across the world, and few names are as synonymous with their industry. Perfect when you need to order more than just a mag drill.
Euroboor: By keeping in a close contact with the end users and listening to their feedback, Euroboor is constantly improving its product line by coming up with new innovations in the industry. Back in 2011, Euroboor was 1st to introduce the cordless mag dill to the market, and recently has launched the new ECO-TUBE.30, the ideal mag drill for pipe drilling with patented technology. With its wide global distribution network and the full range of Magdrills , Euroboor a true specialist in its niche.
Rotabroach: You don’t accrue 40 years of experience specialising in annular cutting technology without staying current with modern breakthroughs. Rotabroach is a natural choice for hole-cutting equipment, and they can provide a comprehensive selection of mag drills, including the venerable Element Series.
Alfra: With a focus on metal core drilling that goes back to the company’s inception in 1979, Alfra possess plenty of experience. Expect a solid range of mag drills, from the compact 9.9kg RB 35 SP to the 2500 watt R 130 4 MT.