Guides / Materials

6061 or 7075 for Your Bike Part

September 3, 2026

Almost every machined bike part is cut from one of two alloys. Picking between them is usually settled by the anodizing, not by the strength numbers.

The short version

	6061-T6	7075-T6
Tensile strength	About 310 MPa	About 570 MPa
Relative material cost	Baseline	Roughly 2 to 3 times higher
Machinability	Good, fast feeds	Good, but harder on tools
Anodizing, Type II	Even color, easy to match	Darker, harder to match batch to batch
Welding	Yes, then heat treat	No, for structural parts
Corrosion resistance	Better	Lower, so anodize it properly

Where 6061 is the right answer

Stems, faceplates, brake adapters, seatpost collars, headset spacers, bottle cages and most e-bike brackets. The sections in these parts are thick enough that alloy strength is not what limits them. You get cheaper stock, faster cutting and a finish that matches across a product range.

If a brand sells parts in five colors, 6061 is what makes that survivable.

Where 7075 earns its price

Cranks, spiders, direct mount chainrings, pivot hardware and anything where you are fighting to remove material and keep stiffness. A crank arm is a long lever with a fixed envelope set by the frame and the rider’s foot. There is no room to solve the problem with more aluminum, so you solve it with better aluminum.

Also worth it on parts where a fatigue test already failed at the section you cannot grow.

What changes at the shop

7075 cuts cleanly but is less forgiving. Tool wear is higher, so a long run costs more in tooling than the material difference alone suggests. Ask the shop to quote both if you are unsure. The delta is usually smaller than people expect on a small part and larger than expected on a heavy one.

What changes at the anodizer

This is the part that causes returns. Type II dye sits in the pores of the oxide layer, and the alloy changes how that layer grows. A black stem in 6061 and a black crank in 7075 from the same bath will not look identical under daylight.

Options, in order of how well they work:

1. Keep a matched set in one alloy.
2. Use a dark color, where the difference is least visible.
3. Ask the finisher to tune separate baths per alloy and accept a tolerance on the match.
4. Move to a painted or coated finish, which hides the alloy but changes the feel of the part.

Putting it on the RFQ

Say the alloy, say the temper and say whether colors have to match another part you already sell. If the design is not frozen, ask for both alloys to be quoted. A shop that machines bike parts every week will tell you quickly which one your geometry actually needs.

Frequently asked questions

Keep reading

• 2014 and 2024 Aluminum: Where These Alloys Fit on a Bike
• When a Bike Part Is Worth Making in Titanium