Entries by Michael Ross

What is Fatigue Failure?

Let’s say you are leaving the house and you see your new credit card on the counter. You replace the expired card in your purse or wallet, but there are no scissors to cut up the old card. So, you start bending it back and fort until it breaks in half; then pitch it. You have just induced a fatigue failure. So too with steel. A piece of steel that undergoes repeated motion (twisting, bowing, […]

Surface Hardening vs. Through Hardening

In the world of heavy industrial maintenance steel, whether you call it Case Hardening, or, Surface Hardening, or, Skin Hardening, it is all the same thing. This is a localized method of hardening employed to develop a wear resistant surface while maintaining a somewhat ductile (shock resistant) core. With production items, such as gear teeth, this may be very fine tuned, sophisticated, accurately measurable. In maintenance, “one-off” items, it can be somewhat erratic and capable […]

Bearing Quality Vs. Bearing Fit

Be careful, the two are often confused between end-user and vendor. They are not interchangeable. BEARING QUALITY refers to manufacturing restrictions that are employed, when the mill makes the steel. It is commonly referred to as “Clean Steel Production”. The processing refines the steel, removing non-metallic inclusions and generally improving the quality and core integrity of the steel. This is not something that can be achieved in subsequent processing; it either is bearing quality, or […]

Centerless vs. On-Center Grinding

Bar Grinding Centerless Vs. On-Centers – Second Part of Four Part Set As we mentioned in our last blog; in the maintenance industry, if someone refers to grinding a steel shaft, they are most likely talking about “Centerless Grinding”. There is another method, however, and that method is called “On-Center Grinding”. A misunderstanding on which method is actually required usually results in expensive errors, and general unhappiness for all parties. Of the two types, centerless […]

Who’s Wallet Comes Out

ALLOWANCE TO FINISH Between the end-user, machine shop, and/or service center, when discussing round steel shafts, there are issues with “allowance to finish”, and even with the method of grinding that will be utilized to produce the finished polished shafts. If subsequent bar finishing or grinding will be done, always let your vendor know what method of grinding will be utilized; are you centerless grinding or grinding on centers. Remember this: “When the bar doesn’t […]

Does Heat Affect Steel?

This is directed to: steel novices, steel challenged, and people who might otherwise cause harm to themselves, those around them, or pieces of steel. So, will steel be affected by temperature? That depends. What Temperature? That depends. Let’s define temperature as “Service Temperature”. That is, the temperature the steel will encounter where it is being used. It is worth mentioning that service temperature may be “Intermittent”, or “Constant”. If the steel is exposed to intermittent […]

Straightness Is Perishable

Bananas turn brown, avocados turn mushy, cars rust. Those are things we recognize as having a shelf-life. They are not permanent. They are perishable. When discussing steel shafting, especially in the field of maintenance, straightness is an important property. If a shaft is received at the end user’s plant bent, It is not usable. You can’t grind it. You can’t machine it. You can’t install it. In fact, unless you are cutting it into little […]

What is the Length of a “Random Steel Bar”?

While there may be typical answers to that question, it is still a little like asking “What is the price of a car?” It depends on a lot of variables. The most universally accepted random bar length would be 12ft random. A close runner-up would be 20ft random. The problem that comes into play is relative to the fact that there is no literal interpretation for random bar lengths. Further, in the steel industry, twelve […]

It’s Not So Obvious

“If you live in a hard-partying area of the country, you may not want to buy a new car that was assembled on a Monday. And, you may not want to shoot pool with someone whose first name is the name of a major city”. Just some considerations learned from experience. In heavy industrial maintenance, seasoned professionals have their own hard-won cautions like the above. Those may not always be obvious. Wouldn’t it be great […]

Does Your Stainless Remember Things?

Most likely it does, regardless of the state of your memory. When I first heard the term “Memory”, relative to stainless steel, I was anxious to find out what it referred to. An associate with one of the stainless mills responded with this little tidbit; “Memory, regarding stainless steel, generally refers to retained stress, specifically in austenitic grades. That relates to “Movement”, or “Walking”. (Bars won’t hold straightness). Those grades of stainless (304L and 316L) […]