Radiator Bleed Key - 9 Sizes to Choose from - 4.5mm / 4.5 mm (Tolerance 4.40-4.60mm)

• IMPORTANT: Use a Vernier Scale to accurately measure your bleed screw to ensure the correct Bleed Key is selected
• Bleed Keys are made to approx 2.4% Tolerance - They can measure +/- 0.1mm
• Sizes available - 4.00mm, 4.25mm, 4.50mm, 4.75mm, 5.00mm, 5.25mm, 5.50mm, 5.75mm, 6.00mm
• New Design - GRIPS 20% Better than standard Bleed Keys
• Efficient Radiator Bleeding: Say goodbye to the hassle and frustration of bleeding your radiator valves with this convenient and easy-to-use radiator key bleed key, UK-wide compatible
• Durable and Long-Lasting Design: Made from high-quality brass, this radiator bleeding key is built to last and withstand frequent use

A 4.5 mm radiator bleed key is designed to fit bleed screws that measure around 4.5 mm across the square. The key itself is made with a small tolerance of 4.40 mm to 4.60 mm, which ensures a snug fit without slipping. Many “standard” radiator keys on the market actually measure 5.30 mm to 5.75 mm, which is too large for normal bleed screws and can easily cause slipping or rounding. To avoid damage, it’s important to measure your radiator’s bleed screw using a vernier/caliper scales so you know which size you need. If you can’t measure it accurately, choosing a 4.75 mm or 5.00 mm key from the newer design range is a safer option, as these sizes cover the most common variations.