3.0 mm reamer

Real precision where it matters most: the Sloting Plus HSS straight reamer Ø3.00 mm

When the fit of an axle makes the difference between a car that runs smoothly and one that vibrates or slips, the tool used to work the hole is not a secondary detail. The SP143730 reamer from Sloting Plus is a high-speed steel HSS tool with Ø3.00 mm and H7 precision, specifically designed to refine holes in aluminium or plastic parts with an accuracy that a tapered reamer simply cannot match.

Technical features

• Material: high-speed steel HSS
• Diameter: Ø3.00 mm
• Tolerance: H7 precision
• Contents: bag with 1 unit
• Application: aluminium and plastic

Why a straight reamer and not a tapered one

The difference between the two types is significant. A tapered reamer enlarges the hole progressively, making it very difficult to control the final size: just a bit too much pressure can result in one end being oversized, the piece becoming tapered, and needing to be discarded. The straight reamer from Sloting Plus works in a completely different way:

• Uniform diameter along its length: the cutting edge always cuts at the same level, without variations from one end to the other.
• Cylindrical hole guaranteed: the result is a perfectly straight hole, without taper, ensuring that the axle fits evenly throughout its depth.
• Predictable fit: the H7 tolerance is standardised, so the coupling with Ø3.00 mm axles falls within real technical precision margins, not approximate.
• No risk of oversizing: having a fixed measurement eliminates the danger of overdoing it and compromising the piece.

Applications in the slot and modelling workshop

This 3.00 mm reamer is particularly useful in preparation and tuning operations where hole precision is critical: adjusting rear axles in plastic or aluminium mounts and supports, refining holes in machined chassis, or any part where a 3 mm axle must rotate or fit without play or excessive tightness. The H7 tolerance is the usual reference in precision sliding fits, making it the logical choice when seeking a repeatable and reliable result.

Correct assembly and use

To achieve the best result, it is advisable to pre-drill the hole slightly below the nominal size (for example, with a Ø2.8 mm drill bit) before using the reamer. Reaming is done with continuous rotational movement in the same direction, without reversing the rotation, applying light and constant pressure. Using light lubricant on aluminium extends the tool's life and improves the surface finish.

Frequently asked questions

What materials is this reamer suitable for?

Sloting Plus specifically designs it for aluminium and plastic, the most common materials in slot preparation parts. It is not suitable for hardened steel or hard abrasive materials.

What does the H7 tolerance mean?

H7 is an ISO standardised tolerance for holes. It defines a fit with a very small minimum clearance relative to the nominal axle, allowing for precise sliding coupling without noticeable play. It is the reference tolerance for axles that must rotate or slide smoothly and accurately.

Do I need a special tool holder to use it?

The reamer can be used with a standard precision chuck, a hand lathe, or a low-speed pillar drill. The important thing is to maintain perpendicularity and not to reverse the direction of rotation during the operation.

Is it reusable or single-use?

It is a reusable tool. With correct use and on the indicated materials (aluminium and plastic), it maintains its cutting edge for a considerable number of operations. Avoiding contact with harder materials extends its lifespan.

What is the difference between this reamer and a conventional drill bit?

A drill bit removes material aggressively, with wide tolerances and a rough surface finish. A reamer refines an existing hole, providing dimensional precision and a clean interior finish. They are complementary tools, not interchangeable.

The Sloting Plus SP143730 is a 3.00 mm HSS straight reamer with H7 precision tolerance, purpose-built for aluminium and plastic parts used in slot car preparation and tuning. Unlike tapered reamers, it delivers a perfectly cylindrical hole with consistent diameter throughout its full length, ensuring accurate axle fit and eliminating the risk of oversizing. An essential precision tool for any serious slot car workshop.