Intro
Precision in woodworking is not about luck — it is about repeatable, measurable accuracy. Anyone who has spent time at a router table or table saw knows the frustration of creeping errors: a blade set a fraction too high, a router bit depth that drifts between test cuts, a fence that sits just slightly out of parallel. These tiny misalignments compound into gaps in joinery, uneven profiles, and workpieces that simply do not fit together the way the plan intended. Eyeballing a measurement against a tape measure or relying on a ruler's thinnest markings is rarely good enough when fractions of a millimetre separate a clean joint from firewood. This is where precision setup tools earn their place — not as luxuries for the obsessed, but as practical time-savers that eliminate guesswork, cut wasted test pieces, and let you move from setup to cutting with confidence. Whether you are dialling in a router table for a production run of cabinet doors or setting a table saw for repeatable dado cuts, having a dedicated set of reference gauges turns a fiddly chore into a quick, reliable step.
Generalities
Setup blocks — also called gauge blocks or height-setting bars — are precision-machined metal bars of known, consistent thicknesses used to transfer measurements directly from a reference surface to a tool. In the context of woodworking, they are most commonly used to set router bit height above the table, table saw blade projection, or the distance between a fence and a cutting edge. When choosing a set, the key factors are the range of thicknesses offered (wider range means more setup options), the material (aluminium is lightweight and resists rust, while steel offers greater durability), the machining tolerance (tighter tolerances mean more reliable measurements), and whether the sizes are clearly marked on each bar. A good set should cover the most common router bit and blade height settings — typically from about 3 mm up to at least 12 mm — in fine enough increments that you rarely need to stack multiple blocks together.
This review looks at a seven-piece aluminium setup block set from POWERTEC, a brand well known in the woodworking accessory space. We cover the included sizes, build quality and machining precision, how they perform in real workshop use on router tables and table saws, and whether they represent good value compared to pricier steel alternatives. We also discuss what these blocks do well — and where simpler alternatives like a digital height gauge might actually be more convenient.
Description
The POWERTEC 71579-P2 is a set of seven precision aluminium setup blocks — sold as a pack of two complete sets — designed to simplify depth and height adjustments on router tables, table saws, bandsaws, and other woodworking machinery. Each set includes seven bars with the following thicknesses: roughly 3.2 mm, 4.8 mm, 6.4 mm, 7.9 mm, 9.5 mm, 11.1 mm, and 12.7 mm (corresponding to 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, and 1/2 inch respectively). These seven sizes cover the vast majority of common router bit and blade projection settings, and because they step in approximately 1.6 mm (1/16 inch) increments, you can combine blocks to dial in nearly any height between 3 mm and 25 mm with good precision. Each bar measures about 149 mm in length and 6 mm thick, giving you enough surface area to make firm contact with both the tool and the reference surface.
The blocks are machined from aluminium and finished in a distinctive blue anodised coating — the same type of finish found on high-end woodworking jigs and fixtures. Aluminium was chosen here over steel for a practical reason: if you accidentally touch a spinning router bit or saw blade with an aluminium gauge block, the soft metal will sacrifice itself without damaging your expensive carbide cutters. Steel blocks, while more durable, can chip or destroy a router bit on contact. Each bar has its thickness clearly printed on the side, so you can grab the right one at a glance without squinting at tiny engravings or reaching for a calliper. The edges are deburred and the surfaces are ground flat — critical for a tool whose entire function depends on being parallel and consistent.
Using these blocks is straightforward and becomes second nature after a few setups. To set router bit height, you place the desired block on the router table next to the bit, lower the bit until it just touches the top of the block, and lock it — done. For table saw blade height, the same principle applies: place the block on the table beside the blade and raise the blade until its highest tooth grazes the top surface. Fence-to-blade or fence-to-bit distance can be set by placing the block between the fence and the cutting edge, sliding the fence into contact, and locking. The main limitation is that these are fixed sizes — if you need an odd height like 10 mm, you will need to stack two blocks (e.g., 6.4 mm + 3.2 mm = 9.6 mm, close enough for most woodworking). For ultimate precision, a digital height gauge will beat any block set, but at several times the cost and with batteries to worry about.
A notable value-add is that this listing includes two complete seven-piece sets in the box — hence the P2 designation. This is genuinely useful in a busy workshop: keep one set at the router table and one at the table saw, or have a backup when one set inevitably gets covered in sawdust on the other side of the shop. The blocks come neatly packaged and include a storage case or sleeve to keep them organised. However, there are no calibration certificates or stated machining tolerances included — something that higher-end metrology-grade gauge blocks always provide. For woodworking, where tolerances of ±0.1 mm are usually acceptable, this is unlikely to be a real-world problem, but it is worth noting for those coming from a machining or engineering background.
Each block is approximately 149 mm long, 6 mm thick, and the width varies with each size. The complete set weighs about 0.93 kg (2.06 pounds) — light enough to toss in a tool bag but heavy enough to sit steadily on a cast-iron table without sliding around. POWERTEC is an established brand in the woodworking accessories market, and while no star ratings are currently available for this specific listing on Amazon.fr, the company has a solid reputation for value-oriented shop accessories. This product is listed under Industrial & Scientific > Test & Measurement > Dimensional Measurement > Gauges > Depth Gauges and is priced at €80.70 on Amazon France — positioning it as a mid-range option between bargain no-name sets and premium steel gauge blocks from machinist brands.
Pros and cons
Pros
- Aluminium construction is deliberately soft — if a block accidentally contacts a spinning router bit or saw blade, it sacrifices itself without damaging expensive carbide cutters, unlike steel gauge blocks.
- The seven-size range covers virtually every common router bit and blade height from about 3 mm to 12.7 mm in fine 1.6 mm increments, and blocks can be stacked for intermediate heights.
- Two complete sets are included in the box — keep one at the router table and one at the table saw, or have a spare for when the first set inevitably walks off to the other end of the workshop.
- Sizes are clearly printed on the face of each bar in large, readable text — no squinting at tiny laser engravings or reaching for callipers to identify which block you are holding.
- At 149 mm long, each block provides plenty of contact surface to sit stably on a cast-iron table and bridge across a router plate insert without tipping or rocking.
- Blue anodised finish resists corrosion in humid workshop environments and makes the blocks easy to spot among the usual clutter of sawdust and offcuts on a busy workbench.
- No batteries, no calibration, no zeroing — unlike digital height gauges, these blocks work instantly every time you pick them up and will never let you down mid-project because of a dead battery.
Cons
- Fixed sizes mean you cannot dial in arbitrary heights — if you need exactly 10 mm you will need to stack blocks and accept the small gap, unlike a digital gauge which gives continuous adjustment.
- No stated machining tolerance or calibration certificate is provided — fine for woodworking but a noticeable omission for anyone used to metrology-grade tools where accuracy is documented.
- Aluminium is lighter and less durable than steel — the blocks can be dented or scratched if dropped on a concrete floor or mishandled, which could eventually affect their accuracy.
- The 6 mm constant thickness means the blocks are not ideal for setting very low projections below about 3 mm — you would need a separate feeler gauge set for sub-millimetre adjustments.
- At €80.70 for what is essentially seven precisely cut bars of aluminium, the price may feel steep to beginners — a simple brass setup bar or a ruler can achieve similar results for far less, just with more fiddling.
Use cases
These aluminium setup blocks are ideal for woodworkers who regularly switch between router bit heights and blade settings and want a fast, repeatable way to set up their machines without test cuts or measurement guesswork.
Router Table Bit Height Setting
Place the appropriate block on the router table next to the collet, lower the bit until it touches the top surface, and lock — you get a perfectly repeatable height every time. Ideal when running multiple workpieces that all need the same profile depth, such as rail and stile door frame components or edge moulding on cabinet face frames.
Table Saw Blade Projection
Set your table saw blade height for dados, rabbets, and grooves without relying on the saw's built-in scale — which is often inaccurate by a millimetre or more. Stack blocks to hit the exact depth of cut specified in your project plans, and get identical results across multiple workpieces without test cuts.
Fence-to-Blade Spacing
Use the blocks as precise spacers between the saw blade and the rip fence when you need a specific offset — for example, setting up a tenoning jig or dialling in the exact width of a groove. Much faster than measuring with a tape and nudging the fence back and forth.
Dado and Groove Depth Checking
After cutting a dado or groove, slide the appropriate block into the slot to verify the depth is consistent across the entire length. The blocks are thin enough to fit into narrow grooves and long enough to check the full depth without tilting.
Bandsaw and Drill Press Setup
Set the distance between a drill press quill stop and the workpiece for repeatable hole depths, or use blocks to set a consistent fence offset on the bandsaw for resawing. The aluminium blocks are light and easy to position in tight spaces around drill press columns and bandsaw tables.