How Much Do Shimano Caliper Bleed Port Screws Weigh?

On the side of every Shimano flat-mount caliper, a small steel bolt seals the bleed port — removed during every brake bleed, tightened to hold mineral oil pressure. You've had an Allen key in it more than once. Here's what it weighs, and what a titanium swap looks like.

Weight Across Groupsets

Identical steel screws across all three groupsets — 4.6g for both calipers combined. Titanium drops that to 1.8g per pair, saving 2.8g. The bleed port dimensions are standardized across Shimano flat-mount road calipers, so there's no weight variance between tiers.

Swap During a Bleed

The bleed port screw is the first bolt you loosen and the last you tighten during any Shimano bleed. It sits on the caliper body with an O-ring underneath that seals against mineral oil. When replacing, transfer the O-ring to the new titanium screw (or use a fresh one — cheap, in most bleed kits). Thread engagement is shallow and aluminum, so light grease on threads is standard with titanium. Torque is low — roughly 1–2 Nm — because the O-ring does the sealing; the bolt just holds it compressed. One minute per caliper, while you're already bleeding anyway.

Finishing the Caliper Hardware

2.8g is a micro-saving, but context matters: if you've already swapped caliper mounting bolts, hose clamp bolts, and rotor lockrings to titanium, the bleed port screws are the last steel parts on your calipers. They're also the bolts you interact with most often — every bleed, every pad change, you're inches from that screw. Swapping them to titanium cleans the caliper hardware completely. Old steel screws in the spares tray, titanium in with fresh O-rings. Done.

TiNE titanium Shimano caliper bleed port screws at tinetech.com