Thread: Scope rings - Steel vs Aluminium

Originally Posted by Chilli_Dog

A couple of little points. There is a big difference in modulus of steel and aluminium, steel is much stiffer. You cant really say steel is this much stronger than aluminium, there are huge variances in strength of both. Friction is not dependent on contact surface area.

Hi there, I would disagree on two points.

firstly, steel is definitely not the stiffer of the two. It is well accepted that when it comes to bicycle materials, steel frame offers a more forgiving, shock absorbing ride. aluminium frames on the other hand is harsher, more punishing because it is stiffer.

secondly, I cannot agree that friction is not dependent on contact surface area. If so all race cars would have skinny tyres.

Originally Posted by Ultimitsu

Hi there, I would disagree on two points.

firstly, steel is definitely not the stiffer of the two. It is well accepted that when it comes to bicycle materials, steel frame offers a more forgiving, shock absorbing ride. aluminium frames on the other hand is harsher, more punishing because it is stiffer.

secondly, I cannot agree that friction is not dependent on contact surface area. If so all race cars would have skinny tyres.

Steel is definitely stiffer than Aluminium. Physics say so.

Unlike strength, which can vary from grade to grade or even coil to coil, Young’s Modulus is constant for a given metal and is independent of heat treatment, processing, or cold work. Young’s Modulus for steel (29 million PSI) is three times that of aluminum (10 million PSI). This means that for a fixed geometry, a part made out of steel will be three times as stiff as if it were made out of aluminum. In other words, an aluminum part under load will deflect three times as much as a similarly loaded steel part.

The thickness and shape of the formed part also contributes to its stiffness. Stiffness is proportional to the cube of the thickness. To neutralize aluminum being one-third the stiffness of steel, an aluminum part must be made 44 percent thicker than the steel part. Even with this increased thickness, there is a potential for weight savings since aluminum is one-third the density of steel.

There are a few steel picatinny rails out there. I have a Warne steel rail on my Rem700, with Leupold steel rings. It's not a hunting rifle so the weight is not a factor. Have alloy picatinny rail and vortex alloy precision rings on my hunting rifle, and they just work too.

Originally Posted by Ultimitsu

Hi there, I would disagree on two points.

firstly, steel is definitely not the stiffer of the two. It is well accepted that when it comes to bicycle materials, steel frame offers a more forgiving, shock absorbing ride. aluminium frames on the other hand is harsher, more punishing because it is stiffer.

secondly, I cannot agree that friction is not dependent on contact surface area. If so all race cars would have skinny tyres.

You are correct on the points I have highlighted.