Walneck's Classic Cycle Trader - February 2009 - (Page 34) MONTHLY FEATURES MOTORCYCLE TIPS do us much good unless we understand grading basics. For regular steel bolts there are four common grades: 2, 5, 8, and 9 with each higher grade being stronger. Any unmarked bolt should be considered a grade 2, but don’t forget the forgery problem. Because of past forgeries, a lot of true grade 2 bolts prior to the Fastener Quality Act carry grade 8 markings and may still be out there somewhere. While forgeries may be tough to spot, interpreting markings on modern hardware is very easy. Aside from the brand imprint, count each line stamped on Aw Nuts Part 1 By Mike Brown J oe Biker reaches for a handful of throttle to bring the front wheel up smartly to jump a small creek. He knows how to position and land properly, having performed this feat so many times he could do it blindfolded. So he flies through the air with the greatest of ease and wakes up four hours later with two broken knees. On a less catastrophic note, I was once forced to install more Helicoil inserts than the kit came with originally because some dufus decided to empty his hardware drawer and used the varied contents to build a BSA A65 motor. I found, no kidding, metric, SAE, Whitworth and I believe a wood screw all brutally jammed and cross-threaded into the soft alloy case. Aww nuts, and bolts too, require a bit more knowledge than matching up the approximate diameter and thread and then grabbing an adjustable wrench. OK, the cause of our first disaster, sheared bolts, can occur for various reasons. Why this can happen is a worthwhile lesson every biker ought to study before reaching into that ol’ bolt bucket during a bike build. First of all, a lot of dangerous fasteners float around and I seriously suspect, given many quality issues making headlines with regularity about inferior products coming from countries like China, that there may well be more being made today. The Fastener Quality Act, originally passed in 1990, but never fully implemented, was watered down considerably and leaves a lot of room for worry. So what does all this mean for the average biker/builder? Quite a lot really. For one example, with a modern fastener you should be able to reliably determine not only the accurate fastener grade and requisite strength, but also trace any marked fastener right back to the manufacturer. This wasn’t always the case. Remember the old joke about the guy who thought forged pistons were against the law? Take this seriously when it comes to fasteners. Prior to the Fastener Quality Act, the U.S. was flooded with cheap imported fasteners stamped with fake grade markings that were then introduced to the market to capture trade by unfairly undercutting domestic competition. As a result of this fraud, and a combination engineering and fastener quality disaster at a Kansas City hotel in 1981 that killed 114 people, the Fastener Quality Act came into being. But the Act itself won’t This bolt just has the manufacturer’s stamp, so it’s a grade 2, the lowest grade and not suitable for high stress applications. Bolt head with no markings should lead to the assumption it is a low grade bolt, and again, not suitable for high stress applications. This is a grade five bolt, an intermediate grade good for many applications. Note the three marks. Add two to the marks you find to determine the grade as required under the Fastener Safety Act. The triangle is the manufacturer’s stamp, also required by the law now. Many fasteners made before the act have all sorts of different markings so just counting marks on unknown hardware to determine grade isn’t always possible. Also be advised if you’re assembling a project and aiming for concours standards, a good judge will know what marks should be on respective hardware, and they’ll look for these marks and deduct points if incorrect. 34 February 2009 | WALNECK’S CLASSIC CYCLE TRADER® I WALNECKS.COM http://www.WALNECKS.COM
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