How to choose a hacksaw and the right blade for the job

The saw matters less than the blade you put in it

A hacksaw is one of those tools that sits in the drawer for months and then saves your afternoon, because it is the only thing in the house that will cut a bolt down, trim a length of threaded rod or take the end off a bit of copper pipe. Most people buy one, never change the blade, and then decide hacksaws are hard work. They are not. The blade is just blunt, or it is the wrong one.

So this is less about which saw to buy and more about what goes in it, because that is the part that decides whether the cut takes a minute or twenty.

What actually matters in the frame

• How tight it goes. A blade you can twist with your fingers will wander and jam. It wants to be tight enough to ring when you flick it.
• How stiff the frame is. A flexy frame lets the blade flex with it, and that is where a crooked cut comes from.
• Whether you can get it in there. A full size frame is no use under a sink, which is the whole reason mini and junior saws exist.
• How it feels after ten minutes. Cutting steel by hand takes a while, and a handle that digs in is a handle you will stop using.

Reading the TPI number, which is the bit nobody explains

TPI is teeth per inch, and the rule behind it is simple enough: you want at least three teeth touching the material at any one time. Too few teeth and they catch on the edge and strip off, which is how people snap blades and then blame the saw.

• 18 TPI. Thick solid stuff, so bar and heavy bolts.
• 24 TPI. The one to have in it if you only keep one. General metal and plastic pipe, which covers most household jobs.
• 32 TPI. Thin wall tube and conduit, where a coarse blade would just tear at it.

Blades also come in high carbon steel and bi-metal. Bi-metal costs a bit more and it is worth it, because the teeth are the hard bit and the back of the blade stays flexible, so it survives being bent rather than shattering.

Plastic, and why it grabs

Plastic melts before it cuts if you go at it hard, and then the swarf welds itself back into the kerf and the blade seizes. Use a finer blade, go slower than feels sensible, and lift the pressure on the return stroke. For PVC conduit and small pipe a junior saw is honestly better than a full size one, because you have got more control and less blade to run away from you.

Timber, and an honest word about it

A hacksaw will cut thin dowel and small trim at a pinch, and that is about as far as it goes. The teeth are too fine for timber, so they clog with sawdust almost immediately and you end up sanding your way through the cut. If you are doing anything more than a dowel, use a handsaw. And if it is a length of structural timber, bring it to us and we will run it through the saw bench and cut it to length while you wait.

Getting a straighter cut

• Let the blade do it. Weight does not make it cut faster, it makes it wander and it makes it blunt.
• Use the whole blade. Short choppy strokes wear out the middle 50mm and leave the rest untouched.
• Cut on the push. Standard hacksaw teeth face forwards, so ease off coming back rather than dragging them backwards under load.
• Start with a nick. Draw back once or twice to cut a groove, then start pushing. The blade will not skate off across the work.

Shop related products

• Supercraft Mini Hacksaw. For the cuts you can barely get your hand to, under a sink or behind a cistern.
• Supercraft Junior Hacksaw, Heavy Duty 150mm. The one most people should own, and the best thing for plastic pipe.
• Supercraft Junior Hacksaw Blades, 10 Pack. Spares, because a fresh blade fixes most hacksaw complaints.
• Supercraft Rod Saw Blade, 300mm. A tungsten rod instead of teeth, so it gets through tile and glass and the hardened bolts that strip an ordinary blade.

Did you know we also stock full size hacksaw frames in store, along with a heavy duty frame, bi-metal 24 TPI blades and 300mm by 12mm blades in 10 packs. They are not on the website, so give us a ring on (08) 8536 4333 to check what is on the shelf.

The rest of the range is at hand tools, and there is more about what we do at the shop on our essential services page.

More from the blog

• What tools do you actually need in a home shed or workshop
• How to organise screws and nails so you can find them
• How to Hang Bikes and Sports Gear on Garage Walls

I keep a spare blade in the drawer with the saw, because I am the sort of person who finds out the blade is stuffed at the exact moment the shop is shut.

Cheers,
Candeece

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