The jeweller's saw frame and its blade are the most essential tools for cutting metal — and because the saw is used so constantly, it pays to invest in the best quality frame and blades available. Inferior blades only lead to frustration: they break easily. The idea of putting a blade in a frame under tension is old enough to have originated in ancient Rome.
Here is what actually matters at the bench: choosing the blade, stringing the frame correctly, cutting with the grain of the tool rather than against it, and knowing why blades snap.
Reading blade sizes
Saw blades cut precious, nonferrous and ferrous metals, and softer materials too — wood, shell, bone, plastics. They come numbered by size, where 8/0 is the finest and 14 the coarsest. Thin metals want fine blades; heavier metals want heavier blades. Most metalsmithing sits in the 3/0 to 1/0 range. Blades are sold by the dozen or the gross (twelve dozen), and they rust in humidity and heat — store them somewhere dry and airtight.
Stringing the frame
Inserting a blade is called stringing, and the sequence matters:
- Loosen the upper and lower thumbscrews to open their jaws.
- Insert the blade's upper end fully into the upper clamp, teeth pointing down towards the handle and outward, away from the back of the frame. Get this wrong and the saw cuts on the upstroke — badly.
- Loosen the back-frame thumbscrew and slide the frame so the blade's lower end just enters the lower jaws, then retighten the back screw.
- Hold the handle toward you, press the top of the frame against the bench edge and the handle against your chest — it feels awkward at first — and use that compression to seat the lower end into the lower jaws.
- While holding the pressure, tighten the lower thumbscrew. Release, and the frame's spring keeps the blade under tension.
Sawing: the working rules
- Always saw on the bench pin, with the metal held tight.
- Keep the blade perpendicular to the metal.
- Catch filings in the filing tray as they fall, and keep filings from different metals separate — they are saved and reclaimed.
- Teeth face down, so metal is removed only on the downward stroke.
- To start a cut (the kerf), place the blade against the metal's edge and draw it upward lightly a few times in the same spot — this groove stops the blade wandering when the real, downward strokes begin.
Blade breakage drops dramatically with a lubricant — plain beeswax run along the blade does the job.
Why blades break
The classic causes, in rough order of frequency: metal not held tightly on the bench pin; too much pressure, forward or downward; sharp changes of sawing direction; a blade clamped too loosely or too tightly; excessive speed; and blade freeze. Every one of them is a habit, not a mystery — which is why sawing is the first skill a metalsmith drills.
Piercing: interior patterns with no edge opening
Piercing is drilling and sawing combined into one technique. Drill a round hole inside the design area — hand drill or motorised — then thread the loose blade through that hole before stringing it onto the frame. Once strung, you can saw out patterns wholly inside the sheet, with no opening along the edge. Combined thoughtfully, drilling and piercing produce any patterned pierced work or fretwork a designer can draw — the kind of layered, openwork silver that makes people ask how it was cut.
Grounded in the JDMIS Metalsmithing (MS100) course materials. Learn these skills hands-on in Foundation Metalwork Skills and Experience; for where sawing fits in the whole construction process, see How Jewellery Is Made and Jewellery Findings Explained.