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Fisrt off, thanks very much again for the new suggestions from TVP, tomwalz, and arunmrao. I downloaded the quaility manual from NADCA, looks like a great start, i also agree with making a simple visual comparson standard based on pics. To answer your question arunmrao, the casting is not...

Coreypad, thanks for the idea about the precision saw and simple water balance. if it shows its below a certain mass then its known to be suspect - and that can be done quickly w/o cutting or mass balances. thank you! Compositepro, we toyed with proof testing however it seems to cost too much...

TVP, thanks for responding. "By visual inspection, do you mean optical examination of a metallographically prepared (sectioned, polished) sample?" Yes, but at our plant we do not want to be polishing or mounting, only sectioning and looking for large voids - internal porosity does not reduce...

Developing a small zinc casting using Zamak5, its not a precision or a thin walled casting, however extreme voids and porosity can result in a structural failure (yielding of the part). What would be a good visual inspection method and standard to use? Of couse we have recommendations from...

Dear eng-tips crew, need your help figuring out requirements for fatigue on this stabilizer bar. Life 100,000 - i get that. Random sample, min six parts - OK got that. Here's where i get lost "The test requirement is for Pu = 50% (actually P sub u double dot), and permissible standard...

tvp, thanks very much. i contacted the baosteel rep.. nothing yet. what is the 7 at the end of 55SiCr7? and in this case, what is the A? just curious.. do the Chinese mills have the equivalents of the very high end steels like UHS1800? Thanks again, Jeff

Hi everyone, i'm trying to find an equivalent to 55SiCrA steel. I dont know much about it, i belive its made in Beijing by Baosteel. Is this ultra high end like micro alloy SRS60? or is it normal like 9259? hmm... Any help appreciated..

BillPSU, i'm thinking about ultra long lasting coatings for automotive metal products.. what are the pro's and cons of a ionomer / poly type coating? I see a lot of patents out there but not to many 'products'.. availabe yet.

Wow, thanks for those awesome responses. Reading as much as i could, there seems to be less and less difference between racing suspension coils, valve springs, or high production hot wound springs. The reason i say this, weight reduction and fuel economy - this is driving the OEM's to higher...

sbozy, i also work for a big coil supplier.. I guess what i'm getting at - how do valve springs and coil springs really differ in peak stress, load loss, etc.. A couple points so far 1. Clean tempered wire is critical for valve springs as most fail due to aluminum oxide inclusions (not...

Thanks everyone. Its a hex end on a torsion bar. the a-datum is called out via GM GD&T (as dingy2 noted). I am a bit confused by the zero. I understand the circled U = unilateral - but the zero is a bit tough to visualize. Powerhound said "The O that you're talking about is more likely a...

Hi everyone, being a coil spring engineer i'm trying to broaden my horizons by looking at other industries, in this case automotive coil springs. I've got some friends who drag race and they go through springs a couple times per season due to huge valve lift, high rpm, large heavy valves, etc...

dingy2.. i finally got the 2003 gd&t spec.. its got that new to me U for unilateral.. also the 'O' for outside.. i can't understand how the datum A, can actually have a profile tolerance. i mean, its a theoretical perfect plane! anyway, the profile is 0.35 U-O.. so its pretty tight. Thanks...

Thanks guys, FYI - UHS1900 is the top of the list.. we use it here rarely.. is it really 1900 Su? (i guess SU really doesn't matter to springs, why do they report it!). Links are excellent. I'm going to SAE conf next year for sure. I've got a few things up my sleeve (see my old posts :) ) My...

Two pronged question about the hex end of a torsion spring. I understand what a profile tolerance is, normally w/o the phantom lines it implies equal bi-lateral profile. However, what if the profile points to a surface that is also a datum? (i.e. A datum of a torsion spring is the hex flat)...

Fellow spring folks, any new materials on the horrizon to replace these alloy's? What are the new cutting edge designs in coil spring materials? i'm curious about what's next from the OEM's.. Lighter, stronger, more corrosion resistant..

Thanks for the excellent responses. Targeting even more, 9254 vs. srs60.. any thoughts? sbozy25, variable rate and pitch.. now that is the way to go although processing is a headache! TVP, the goal of the engineer is to save weight not cost so much.. but purchasing loves to make things hot...

Sbozy25 wrote: "FYI if you go with a 5160 for example and say you centerless grind the bar before forming the part, it might come out slightly more cost effective. " We are being forced to go turn and polished (peeled and burnished, what ever it is..) as CG shops are going out of business. I...

Thanks Sbozy and CoryPad. I had no idea SRS60 was so expensive.. If we had to rank them in terms of grain size? Sag resistance? Decarburization potential? Ultimate and shear strength? Potential to be used in as rolled condition? I believe Sbozy you ranked them in the composite...

Spring folks, I'm looking at hot formed quenched and tempered sprigns for the automotive industry. I know the chemical compositions of each.. but i don't know the engineer's characterization of 9254, 9259, 9260, or SRS60. Have you guys worked with these steels? What is the good / bad / ugly...