1.5 Hand Tools, Portable Power Tools & Shop Machines
Key Takeaways
An abrasive wheel must carry a maximum rated speed equal to or greater than the spindle speed of the tool it is mounted on, and must be ring-tested before mounting.
On a bench or pedestal grinder the work rest is set within 3 mm of the wheel and the tongue guard within 6 mm, and both are re-adjusted as the wheel wears.
Impact wrenches are never used to set a final torque value; they seat the fastener and a calibrated torque wrench then establishes preload.
Mushroomed chisel and punch heads must be ground back, because the work-hardened rim breaks off as high-velocity fragments when struck.
Work in a drill press must always be clamped or held in a vise — a drill grabbing an unclamped part turns it into a rotating blade, and gloves must never be worn at any rotating machine.
Task A-2 (Uses tools and equipment) carries 5 of the 25 questions in Major Work Activity A, split across hand and portable power tools, shop machines, and access equipment. These questions are practical and specific — guard clearances, wheel speeds, and the tools that must never be used for a given job.
Hand Tools
| Tool | Selection and safety points |
|---|---|
| Wrenches | A 6-point socket or box end grips the flats and is preferred on tight or rounded fasteners; a 12-point offers more engagement angles but concentrates load on the corners. Pull a wrench, never push, so a slip does not drive your knuckles into the machine |
| Striking (slugging) wrench | Heavy box wrench struck with a hammer for large flange and bearing nuts; use only where designed, and never strike a standard wrench |
| Torque wrench | Beam, click, dial and digital types. Never use a torque wrench to loosen a fastener, and back a click wrench off to its lowest setting for storage so the spring does not take a set |
| Torque multiplier | Planetary gearbox that multiplies input torque; the reaction arm must bear on a solid surface, never on a hand or a hose |
| Pliers and channel locks | Gripping and holding only; never use as a wrench on a fastener that must be reused |
| Screwdrivers | Match tip and shank to the fastener; a screwdriver is not a pry bar, chisel or punch |
| Hammers | Ball peen for metal work, dead blow for assembly without marring, sledge for heavy work. A loose or cracked handle takes the hammer out of service |
| Chisels and punches | Struck-tool heads work-harden and mushroom; the mushroomed rim breaks off as shrapnel when struck. Dress heads back to a slight chamfer on a schedule |
| Files | Single cut for finishing, double cut for fast removal. Never use a file without a handle — the tang will go through a hand if the file catches |
| Hacksaw | Blade TPI chosen so at least three teeth contact the work; too coarse a blade straddles thin material and strips teeth |
| Pullers | Two- and three-jaw, hydraulic, and slide-hammer types. Centre the puller screw on the shaft end, protect the shaft centre, and never heat a bearing while a puller is loaded unless the procedure calls for it. Always drape a blanket over a loaded puller — a jaw that lets go becomes a projectile |
Portable Power Tools
Electrical safety:
- Tools must be CSA-certified and either Class I (grounded, three-prong) or Class II (double insulated, two-prong with the double-square symbol). Never remove a ground pin.
- A ground fault circuit interrupter (GFCI) is required for portable tools used outdoors, in wet locations, and in most construction and confined-space work.
- Inspect cords before every use; remove tools with damaged cords, cracked housings or defeated guards from service and tag them.
- Do not carry a tool by its cord, and unplug before changing accessories.
Pneumatic tools: connect with a safety whip check or restraint cable across each coupling, because a hose that separates under pressure whips violently. Never point an air nozzle at a person, and limit air blow-gun nozzle pressure per the applicable regulation.
The impact wrench rule. An impact wrench delivers uncontrolled, highly variable torque — it is a seating tool, not a torquing tool. Fasteners that require a specified preload (bearing lock nuts, coupling bolts, flange bolts, cylinder head bolts) are run down with an impact and then finished with a calibrated torque wrench or a tensioner.
Abrasive Wheels and Grinders
Abrasive wheel failure is one of the most severe injury sources in a shop.
- Speed rating. The wheel's maximum rated RPM printed on its blotter must be equal to or greater than the no-load spindle speed of the tool. Never fit a 6,000 RPM wheel on a 10,000 RPM angle grinder.
- Ring test. Before mounting, suspend the wheel on a pin and tap it lightly with a non-metallic handle about 45 degrees each side of vertical. A clear ring means the wheel is sound; a dull thud means it is cracked — destroy it.
- Mounting. Use matched flanges of the correct diameter with blotters (paper washers) on both sides. Tighten the nut only enough to drive the wheel; over-tightening cracks it.
- Run-in. After mounting, stand to the side and run the wheel at operating speed for a full minute before use.
- Bench and pedestal grinder guarding: the work rest is set within 3 mm (1/8 in) of the wheel face and the tongue guard within 6 mm (1/4 in) of the wheel periphery. Both must be re-adjusted as the wheel wears down. A gap larger than that lets the work be dragged down between the rest and the wheel.
- Side grinding. Only wheels specifically rated for side loading (such as a Type 27 depressed-centre wheel) may be used on their side. Grinding on the side of a straight Type 1 wheel can shatter it.
- Always wear a face shield over safety glasses when grinding, and never grind aluminum, brass or wood on a wheel intended for steel — soft metal loads the wheel and causes bursting.
Shop Machines (A-2.02)
| Machine | Key safety and technique points |
|---|---|
| Drill press | Clamp the work or hold it in a vise. A drill that grabs spins an unclamped part into a rotating blade. Select speed from the cutting-speed formula for the material and drill size, use cutting fluid on steel, and peck-drill deep holes to clear chips |
| Engine lathe | Remove the chuck key before starting — this is the single most common lathe injury cause. Set the tool bit on centre height, guard the chuck, never measure or clean chips while the spindle turns, and use a brush not fingers for chips |
| Milling machine | Secure the work in a vise or clamp it to the table; understand climb versus conventional milling; stop the spindle before measuring |
| Horizontal / vertical band saw | Match blade TPI to material thickness (three teeth in the cut), adjust the guides close to the work, and keep the upper guard down to the minimum working height |
| Hydraulic press | Never exceed the rated capacity; use the shield, chain the workpiece or use a press guard because parts fly when they release, and stand out of the line of the ram |
| Pedestal grinder / abrasive chop saw | As above, plus secure clamping and spark direction away from combustibles |
Universal machine rules: no gloves, loose sleeves, jewellery or unrestrained long hair at any rotating machine; guards in place; lock out before changing belts, gears or making adjustments inside a guard; and never leave a machine running unattended.
Fabricating a Work Piece (A-3.02)
The standard sequence a millwright follows to make a part:
- Read the drawing and confirm material, dimensions, tolerances and finish.
- Select and verify material — the right grade and enough stock allowance for machining and cutting kerf.
- Lay out from an established datum (see section 15.5).
- Cut oversize, leaving machining allowance.
- Machine to size, working from the datum, roughing then finishing.
- Drill, tap, bore and key as required.
- Deburr and break sharp edges — a burr causes assembly interference and a sharp corner is a fatigue initiator.
- Verify every dimension against the drawing before the part leaves the bench, and record any deviation.
A millwright is about to mount a new 180 mm abrasive wheel on an angle grinder with a no-load speed of 8,500 RPM. The wheel blotter reads "Max 6,600 RPM". What is the correct action?
Do not mount the wheel — obtain one rated at or above 8,500 RPM, because a wheel run above its rated speed can burst
Mount the wheel and perform a ring test to confirm it is sound at the higher speed
Mount the wheel with an extra flange to contain any fragments
Mount the wheel but run the grinder at reduced trigger pressure
A coupling manufacturer specifies 285 N·m on the coupling bolts. Which method establishes that preload correctly?
Run the bolts down with a 1/2 in impact wrench set to its highest power setting
Seat the bolts with an impact wrench, then set final torque with a calibrated click-type torque wrench in a criss-cross pattern
Tighten by feel with a long breaker bar until the bolts stop turning
Use an impact wrench and count three seconds of hammering per bolt
On a pedestal grinder, the work rest sits 6 mm from the wheel and the tongue guard sits 15 mm above the wheel after several weeks of use. What must be done?
Remove the tongue guard to allow better visibility of the work
Nothing — these clearances only apply when the wheel is new
Re-adjust the work rest to within 3 mm and the tongue guard to within 6 mm of the wheel, since both must be maintained as the wheel wears
Replace the wheel, because the clearances cannot be re-adjusted
Sections you finish are checked off in the contents.