Grade 2 vs Grade 5 Bolts/Washers

Will I notice a difference if I use grade 2 fasteners rather than grade 5 fasteners?

A store in the US called Tractor Supply is selling grade 2 nuts/washers for $2 a pound (which is about 100 nuts/washers), and it seems like a good deal.

i just use whatever i can find to bolt things together. i don't think abs is stronger than a grade 2 bolt, however here is link to a bolt chart from google [www.boltdepot.com]

Low or medium carbon steel tensile strength is ~60000psi
abs tensile strength is 6500psi
abs and plastic materials charts

[www.machinist-materials.com]

not a rocket scientist here, and not sure it is apples to apples comparison, but basically you are still holding abs plastics together with something that is 9.2 times as tensile. so from my perspective who cares, your abs plastic will be pulverized well before the bolts give way. hope that helps.

Greetings all,

The grade of (steel) fasteners is a measure of their strength and how well they've been tested. Increasing grade means stronger steel and better testing. Mild steel (A36, as used in bridges, etc. has a yield strength of 36,000 lbs/inch^2); no plastic yet extruded by a reprap comes close, even allowing for heat-induced softening of the steel. Short answer: grade 5 won't hurt for a reprap, but isn't IMHO worth any added cost.

The only scenario I can foresee where grade 5 fasteners would make sense is if you're building a combination milling/repRap. Vibration and related cutting forces can be quite high, depending on what you're cutting and how big and fast a cut you're attempting.

Hope this helps

What I need to understand between the grade 2 and grade 5 hardware is the wear resistance. Some grain is so abrasive the bolt head is wearing off too soon.

Grade 2 is fine. Grade 5 is overkill for a printer. The pricing at TSC is pretty good particularly for a small batch. When you get into commercial or production quantities fasteners are sold by the weight and not the count. A package of 100 M8 zinc nuts (5/16" is abou the same) is about a pound. One of my packs weighs 16.2 oz.

Thanks for sharing the links. It is always best to have enough knowledge about different fasteners to make sure that you are using the right one. Using the right fasteners can help make the hold stronger and also for it to last longer.