Router bits are one of the most versatile accessories in any workshop, but buying the wrong shank size — or using an incompatible bit with your collet — is one of the most common mistakes made by trade and DIY users alike. This guide covers everything you need to know about router bit compatibility in 2026: shank sizes, collet fitment, RPM ratings, and brand-by-brand specifics.
Whether you’re running a Makita RT0700C trim router, a DeWalt DW625EK plunge router, or a Festool OF 1400 EBQ, we’ll show you exactly which bits fit — and which to avoid. Every table here is built from manufacturer specs, verified against real-world use.
Quick Router Bit Compatibility Reference
Use this table to identify which shank size your router accepts. For brand-specific guides with model-by-model compatibility, see the sections below.
| Router Type | Typical Shank Size | Collet Options | Typical Use |
|---|---|---|---|
| Palm / trim router | 1/4″ (6.35mm) | 1/4″ (6mm optional) | Edge trimming, small profiles |
| Mid-size plunge router | 1/4″ or 8mm | 1/4″, 6mm, 8mm | General joinery, dadoes |
| Heavy-duty plunge router | 1/2″ (12.7mm) | 1/2″, 1/4″, 8mm | Raised panels, large profiles |
| Router table fixed router | 1/2″ (12.7mm) | 1/2″, 1/4″ | Production work, large bits |
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How Router Bit Compatibility Works
Router bit compatibility comes down to three things: shank size, collet fitment, and RPM capability. The shank is the cylindrical part of the bit that clamps into the router’s collet. If the shank and collet don’t match exactly, the bit will either not fit or will slip under load — both dangerous.
Most 1/2 inch routers in the UK ship with both a 1/2 inch and a 1/4 inch collet, making them the most flexible choice. Palm routers (trim routers) are almost always 1/4 inch only. European brands like Festool and some Bosch premium bits use 8mm shanks, which are a halfway-house size with better rigidity than 1/4 inch and lower cost than 1/2 inch.
Key Compatibility Factors
Before buying a router bit, always check these four things:
| Factor | What to Check | Why It Matters |
|---|---|---|
| Shank diameter | 1/4″, 8mm, or 1/2″ — must exactly match your collet | Wrong size won’t fit or will slip under load |
| Shank length | Minimum 19mm (3/4″) engaged in the collet | Too short = dangerous; can bend or break |
| Maximum RPM | Must exceed your router’s operating speed at that bit diameter | Exceeding rated RPM can shatter the cutter |
| Bearing size (bearing-guided bits) | Matches the profile dimensions you need | Wrong bearing = wrong offset from edge |
Shank Sizes Explained
1/4 inch (6.35mm) Shank
The most common shank size in the UK and US. Fits every palm router and most mid-size routers. Best for bits up to around 35mm cutting diameter. Above that, the 1/4 inch shank flexes under load and can snap — stick to 1/2 inch for larger cutters.
8mm Shank
A European-favoured size pushed by Festool, Trend (CraftPro range), and some Bosch Professional bits. More rigid than 1/4 inch, lighter than 1/2 inch. If your router came with an 8mm collet, you can use 8mm bits — but you cannot use 8mm bits in a 1/4 inch collet.
1/2 inch (12.7mm) Shank
The professional standard. Essential for bits over 35mm cutting diameter, raised-panel cutters, and router-table work. Stiffer shank = less chatter, cleaner cuts, longer tool life. Every 1/2 inch router accepts 1/4 inch bits via a reducer collet.
Brand-by-Brand Router Bit Compatibility
We’ve created detailed compatibility guides for every major router brand sold in the UK. Click through for model-by-model tables, recommended bits, and where to buy.
| Brand | Key Models Covered | Full Guide |
|---|---|---|
| Makita | RT0700C, RP0900X, RP2301FCX, 3612C | Makita Router Bit Guide → |
| DeWalt | DW625EK, DWE6000, DCW600, D26204K | DeWalt Router Bit Guide → |
| Bosch | POF 1400 ACE, GOF 1600 CE, GKF 600, GMR 1 | Bosch Router Bit Guide → |
| Festool | OF 1010, OF 1400, OF 2200, MFK 700 | Festool Router Bit Guide → |
| Triton | TRA001, JOF001, MOF001 | Triton Router Bit Guide → |
| Trend | T3, T4, T5, T7, T11, T14 | Trend Router Bit Guide → |
| Freud | FT1700, FT2000E, FT3000VCE | Freud Router Bit Guide → |
| Milwaukee | M18 FTR, 5615-20 | Milwaukee Router Bit Guide → |
| Ryobi | R18TR, ERT1150V | Ryobi Router Bit Guide → |
| HiKOKI | M12V2, KM12VC, M8V2 | HiKOKI Router Bit Guide → |
How to Check Router Bit Compatibility
Follow this simple four-step check before buying any router bit:
Step 1: Identify your router’s collet size. Check the manual, the spec sticker on the router body, or measure the internal diameter of the collet with a vernier caliper. Most routers have this marked on the spindle or near the collet nut.
Step 2: Measure or check the bit shank. Router bits are marked with the shank size on the shank itself. 1/4 inch bits measure 6.35mm, 8mm bits measure 8mm exactly, 1/2 inch bits measure 12.7mm.
Step 3: Confirm the bit’s maximum RPM. This is usually stamped or laser-etched on the shank or cutter body. If your router runs faster than the bit’s rating at a given speed setting, dial it back.
Step 4: Check cutter diameter vs shank. Anything over 35mm cutter diameter should be on a 1/2 inch shank. If you have a 1/2 inch bit but only a 1/4 inch router, you need a larger router — not a reducer sleeve.
For a detailed walkthrough with pictures, see our router collet compatibility guide.
Where to Buy Router Bits in the UK
Router bits are available from a wide range of retailers. For trade-quality TCT bits, we recommend Trend’s Professional range, Freud’s Diablo series, and CMT Orange Tools. Budget-conscious users will find Silverline and Titan adequate for occasional home use.
Buy Router Bit Set (1/4 inch) on Amazon UK
Buy Router Bit Set (1/2 inch) on Amazon UK
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Related Guides
Explore our other compatibility guides to make sure all your workshop accessories work together:
- 1/4 vs 1/2 Inch Router Bits — Which Shank Size?
- 8mm vs 1/4 vs 1/2 Inch Router Shank Sizes
- Router Collet Compatibility Guide
- Multi-Tool Blade Compatibility Guide
- Planer Blade Compatibility Guide
Frequently Asked Questions
What shank sizes do router bits come in?
Router bits are made in three main shank sizes: 1/4 inch (6.35mm), 8mm, and 1/2 inch (12.7mm). In the UK, 1/4 inch and 1/2 inch dominate — 8mm is mainly used by European brands like Festool and some Bosch bits. The shank size must match the collet fitted to your router.
Can I use a 1/4 inch router bit in a 1/2 inch router?
Yes, provided the router accepts a 1/4 inch collet or a reducer sleeve. Most 1/2 inch routers ship with a 1/4 inch collet as well, so you can swap between sizes. Never force a 1/4 inch bit into a 1/2 inch collet — use the correct size collet.
Are router bits universal across brands?
Router bits themselves are universal — a 1/4 inch shank fits any 1/4 inch collet regardless of the router brand. The exception is proprietary systems like some Festool OF 1010/1400 routers using 8mm shanks and Trend’s T-series which often prefers 1/2 inch for heavier cutters.
What’s the difference between HSS and TCT router bits?
HSS (High Speed Steel) bits are cheaper and sharpenable but dull quickly on hardwood or MDF. TCT (Tungsten Carbide Tipped) bits hold their edge 10–25× longer and handle abrasive materials like MDF, plywood and hardwoods far better. For most DIY and trade use, TCT is the better choice.
What’s the maximum RPM for a router bit?
It depends on bit diameter. As a rule of thumb: up to 25mm diameter run at 22,000–24,000 rpm; 25–50mm at 18,000–20,000 rpm; 50–75mm at 12,000–14,000 rpm; over 75mm run at 8,000–10,000 rpm. Always check the bit’s own marking — exceeding it is dangerous.
Do I need a collet reducer or a matched collet?
A matched collet (full-size to the bit shank) is always better than a reducer sleeve. Reducers are acceptable for light work but can cause runout and vibration, especially at higher rpm. Most quality routers ship with multiple collets — use the right one.