True that many of the parts that are engine internal are not going to be AN rated and don't forget the very important words,
or equivalent. Metric bolts also have 2 fastener grades available the hex head bolts will be marked 8.8 (a grade 5 equivilent) or 10.9 (a grade 8 equivalent) both of which are readly available on line.
www.boltdepot.com was listed before and they list a good selection. You will find a great many of the bolts in the engine compartment of your Mazda are marked 8.8, unless there in a non critical area. engine mount bolts and other high strength are often 10.9 stamped. My point is not to assume a non stamped bolt at the box store is up to snuff. I'm taken aback often when I see an otherwise 10 of 10 quality job with junk fasteners in it. I won't even tell you some of the stuff I saw at the motorcycle races. I protested several for general contestant safety, including my own. I was hit and crashed by a failure of one of these guys so maybe I'm sensitive? These are general reminders not trying to beat anyone over the head. Everybody simply needs to use their head. The rod bolts in my buddies Cosworth BDJ have no markings, but they are super tough, x-rayed, magnafluxed, tempered high strength items. Again trust is the issue get your stuff from a good source, which can even be the corner hardware if you're careful.
Bill Jepson
-----Original Message-----
From: Ernest Christley <echristley@nc.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, 27 Mar 2008 11:45 am
Subject: [FlyRotary] Re: Metric Bolts
wrjjrs@aol.com wrote:
> There is absolutely no reason to have a hardware failure. None of us should be using non-AN nuts and bolts for any sagnifigant part. Come on guys this is not an area to scrimp.
> This is the Flyrotary list. Every one will have to use a great many non-AN nuts and bolts for a very significant part...the rotary engine. There are no AN metric parts. It's not just about saving a few cents. Aircraft Spruce and Wicks prices are not out of line with other quality bolt distributors, but their online catalogs don't even list any metric bolts that I could find; though, I seem to remember some of the same zinc plated stuff that Lowe's has listed in ACS's printed catalog.
You can run a test on the bolts you get. A spring type torque wrench and a block of aluminum. Mount the head of the bolt in a vice, pass it through the aluminum, and apply the torque wrench until the threads strip. A couple from various batches will let you know real quick what is usable. I used lots of the hardware store Class 5 1/4" bolts to hold parts together when welding. The Class 3 were not strong enough to be worth keeping around, and I didn't want to weld around the cadmium plating of the Class 8 or AN bolts (burning cadmium is a carcinogen). The AN were no stronger than the Class 5, by measure of my semi-calibrate wrench hand.
The Class 5 hardware stuff is worth crap for corrosion resistance, though. I had the oil pan stuck on the bottom of my engine for a few years, while it sat at the back of my workshop. Used some of the Class 5 hardware store bolts, because the original oil pan bolts weren't long enough. About half came out with powdery white rings of corrosion. The trick is going to be finding a good selection of cadmium plated, Class 5, drilled-head, metric bolts. Then put together an order list that will cover most everyone's needs.
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