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?
A coupling manufacturer specifies 285 N·m on the coupling bolts. Which method establishes that preload correctly?
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?