The Fastener Training Minute with Carmen Vertullo

Technical training lessons from the Fully Threaded Radio archives by the guru of AIM Test Lab

carmen vertullo

In a bolted joint, should the nut be stronger than the bolt? (Episode 148, 01/18/2020)
On episode 148 we took another question from the certified Fastener specialist training program.

The question has to do with bolted joints. And the question is: In a bolted joint should the nut be stronger than the bolt?

The answer is that in a bolted joint the nut should be ...[More]

Is Heat Treating used to change the physical properties of fasteners? (Episode 147, 12/15/2019)
In episode 147 we take a question from the certified Fastener specialist training program.

The question has to do with heat treating and the question is: Is Heat Treating is used to change the physical properties of Fasteners?

The answer to that question is true.
That's exactly ...[More]

Is Heat Treating used to change the chemical properties of fasteners? (Episode 146, 11/15/2019)
Some of you might know that the faster training institute has one of their infamous or famous, depending upon which side you're on, Certified Fastener Specialist week-long training programs coming up in La Mirada, California the first week of December 2019, and I hope you'll attend that class.

How do we measure, and what is the Shear Strength of a fastener? (Episode 145, 10/15/2019)
Today's topic is a very important property of fasteners called Shear Strength.

Now strangely enough, it's a very unusual property in that we very seldom actually test for the Shear Strength of fasteners.

It's important for engineers to know the Shear Strength.

How can th...[More]

Why do we passivate Stainless Steel fasteners? (Episode 143, 08/18/2019)
Stainless steel is a corrosion resistant alloy ; this is one of the properties of stainless steel. Stainless Steel is made from a number of elements, one of which is chromium. It's Chromium that makes stainless steel stainless. When the surface of stainless steel is exposed to air, it develops a ve...[More]

Do you torque the bolt or the nut, or does it even matter? (Episode 118, 07/28/2017)
I had a question recently which has actually come up many times in the past and its one that's often put to suppliers of hardware nuts and bolts and the question is this: does it make any difference in joint tightness if the tightening torque is applied to the bolt or the nut in a connection which h...[More]

Washers: Use and Misuse (Episode 90, 02/12/2015)
Washers seem to be relatively simple animals. They've got no threads.  They've got a hole. They've got an inside and outside diameter, and a thickness.  And if it's a lock washer, it's got some other things going on. There is a lot more to know about washers than you ever thought and a lot of mone...[More]

Coarse Threads vs. Fine Threads (Episode 88, 11/13/2014)
Recently, a client of mine had advised a customer who needed some fine thread bolts that they couldn't get, to use coarse thread instead, because they were "stronger", or "better" was the actual word he used.

Well, it turns out, because of the geometry of threads in every case, when the mat...[More]

The Importance of Proper Paperwork (Episode 87, 10/17/2014)
A recent visit to a very important national defense facility was based on the fact that they were having some real problems with paperwork coming with their fasteners through the distributors that were providing them. It's always been my feeling that as fastener suppliers, one of the things we get ...[More]

Boron Steel in Fasteners (Episode 85, 08/26/2014)
Most of you probably know that over the past decades, boron steel got kind of a bad rap for some undeserved reasons. It's actually a very important material.  It helps us to make fasteners cheaper and easier. Boron steel allows us to use steel with less carbon to make higher strength fasteners. One ...[More]

Structural Bolting Suppliers (Episode 83, 06/12/2014)
Every experienced structural bolting supplier has war stories about things that have gone horribly wrong with structural bolt transactions or installations. Those fastener suppliers who only dabble in the structural bolting niche soon find out about the inherent risks associated with supplying str...[More]