How to Read a Scroll Saw Blade Package: Teeth Per Inch and Width

A scroll saw blade packet can look confusing when it combines teeth per inch, blade width, thickness, tooth style and material codes in a small space. These markings are practical specifications rather than advertising language: they indicate how aggressively the blade cuts, how tightly it can turn and which materials it can handle.

For Australian woodworkers, choosing the right blade matters when working with native hardwoods, craft plywood, acrylic or thin laminates. A blade suited to a delicate marquetry pattern may struggle in dense jarrah, while a coarse blade that works quickly through thicker pine can leave a rough edge on a small indoor project.

What Teeth Per Inch Means

Teeth per inch, commonly shortened to TPI, tells you how many cutting teeth appear along one inch of blade length. A high-TPI blade has small, closely spaced teeth. It generally produces a finer cut and gives better control on thin stock, although it removes material more slowly and can clog if the workpiece is too thick.

A low-TPI blade has fewer, larger teeth. It clears sawdust efficiently and cuts thicker timber faster, but the kerf is usually more visible and the edge may need extra sanding. TPI should therefore be considered alongside material thickness rather than treated as a simple quality rating.

Packages sometimes show a range, such as 15–20 TPI, because the blade has variable tooth spacing. This arrangement can reduce vibration and help prevent a repetitive pattern of tooth marks. It is useful when cutting plywood, hardwood or shapes that change direction frequently.

Reading product descriptions also benefits from the same attention to detail used when checking any specialist information. For example, a protected play guide may distinguish between several similar terms, just as a blade label separates tooth count from blade width. The important point is to identify what each number actually measures.

How Blade Width Affects Control

Blade width is the distance across the blade, usually listed in inches or as a numbered scroll saw blade size. Narrow blades turn more easily, making them suitable for tight internal corners, lettering, fretwork and intricate portraits. Their flexibility is valuable when a pattern contains small loops or abrupt changes in direction.

Wider blades are stiffer and tend to track straighter. They are better for longer cuts, thicker wood and designs where a stable line matters more than a very tight turning radius. A wide blade can be easier to control for a beginner because it resists twisting, though it may not follow a small radius without binding.

Thickness is related to width but is not identical. A package may list both dimensions, and the thicker blade will usually withstand more pressure while producing a slightly wider kerf. If a pattern requires a narrow entry hole for an internal cut, check the blade thickness as well as the nominal size.

Many imported scroll saw blades use imperial measurements, even when the user works in millimetres. Australian makers commonly buy materials labelled in metric sizes, so it helps to compare the blade specification with the actual thickness of the plywood or timber rather than relying on a size number alone.

Matching TPI And Width To Material

For thin plywood, veneer and small craft parts, choose a fine or medium-fine tooth pattern with a narrow-to-medium width. A blade in the higher TPI range can leave a cleaner edge on 3 mm sheet, especially when the design includes tight corners. Feed the material steadily; forcing it into a fine blade can overheat the teeth or cause them to strip.

For thicker pine, hardwood or layered plywood, a medium TPI blade with a little more width is often easier to manage. Dense Australian species such as spotted gum, jarrah and blackbutt can place considerable load on a small blade. Slowing the feed rate, keeping the table clear of dust and using a sharp blade are more effective than simply selecting the most aggressive tooth pattern.

Acrylic requires a different approach. Very coarse teeth can chip the edge, while excessive heat may soften or melt the cut line. A fine-tooth blade, moderate feed pressure and occasional pauses can produce a cleaner result. Test on an offcut first, particularly when working with cast acrylic, mirrored sheet or coloured plastic.

Woodworkers who move between timber, acrylic and fabric-related craft work may also compare specialist suppliers and material ranges. For complementary quilting and fabric projects, quilting supplies can sit alongside a scroll saw setup, particularly when a workshop produces wooden templates, appliqué forms or display pieces.

Reading Tooth Styles And Package Codes

Tooth style is often printed beside TPI and width. Standard tooth blades have evenly spaced teeth and are a dependable general-purpose choice. Skip-tooth blades leave a larger gap between cutting points, which improves chip clearance and can reduce clogging in softer or thicker materials.

Reverse-tooth blades have some teeth pointing upward and others pointing downward. They are designed to reduce splintering on the top and bottom surfaces, although the cut may be slower and the blade can require more careful alignment. They are particularly useful for decorative plywood where both faces will remain visible.

Spiral blades have teeth around the full circumference, allowing the cut to move in multiple directions without rotating the workpiece. That convenience comes with reduced visual control: it is harder to see precisely where the cut is travelling, and the resulting kerf may be wider or less clean. Spiral blades are best chosen for suitable patterns rather than as a universal replacement.

When examining a packet, look for these details:

Teeth per inch or a TPI range
Blade width and thickness
Tooth configuration, such as skip, reverse or spiral
Recommended material thickness
Whether the blade has plain ends or pinned ends

Plain-end blades are held by the saw’s clamps and suit many modern scroll saws. Pinned blades have a cross-pin at each end and only fit machines designed for that style. A package may also identify blade length, which must match the saw’s upper and lower clamp spacing.

Using The Label To Plan A Clean Cut

Start by reading the material recommendation and maximum thickness, then compare it with the project stock. A blade advertised for thin fretwork should not be expected to perform well in 25 mm hardwood. If the label gives only a size code, check the manufacturer’s chart for the corresponding width, thickness and typical use.

Australian workshop conditions can affect the result. In a humid coastal city such as Brisbane or Sydney, plywood may move slightly after it comes indoors, while a dry Adelaide or Canberra workshop can produce different dust and static conditions. Store blades in a dry container, keep timber flat and allow sheet goods to acclimatise before cutting detailed patterns.

The saw itself also influences how the printed specifications behave. Correct tension helps a narrow blade track accurately, while excessive tension can shorten blade life. Set the speed according to the material, keep the table square and let the teeth do the cutting instead of pushing the workpiece forcefully.

A practical selection guide looks like this:

Fine TPI and narrow width for thin plywood, lettering and tight curves
Medium TPI and medium width for general scroll saw work
Lower TPI and wider blades for thicker timber and straighter cuts
Reverse-tooth designs for reducing splintering on visible faces
Spiral blades for multidirectional cuts where edge refinement is less critical

Before beginning a finished piece, make a short test cut in the same material and thickness. Check the top and underside for splintering, measure whether the kerf is acceptable and see how tightly the blade turns. A few minutes of testing can prevent a detailed pattern from being ruined by an unsuitable tooth arrangement.

Sloan’s Woodshop offers scroll saw blades, plywood, acrylic and related accessories through its Sloan’s Woodshop catalogue, with product assistance available by phone. Since the business is based in Tennessee and ships within the United States, Australian customers should confirm shipping availability, import charges and delivery arrangements before ordering. Local makers in Melbourne, Perth or regional New South Wales may also need to allow for currency conversion and the time difference when calling.