New Calibration Lab Almost Ready January 12 2016
Skidmore-Wilhelm recently acquired a production facility which included space for a new calibration lab. We began work immediately to optimize the space to support the flow of calibration work that moves through our shop on a daily basis.
When completed our lab will be a state of the art facility allowing us to efficiently calibrate Skidmore-Wilhelm units and quickly return them to the field performing at their original factory specifications.
Reminder Program Launched
We have also recently started sending out emails as part of our new calibration reminder program. If you used our online calibration request form and asked to receive a reminder you can expect to receive an email about one month before it’s due. We hope to expand this feature in 2016 in an effort to help simplify the calibration process.
Our goal is to provide superior support regardless of the calibration cycle specified by your quality requirements. If you want join our expanding program simply check the "Yes" box next time fill out the form on our Online Calibration Request page.
Skidmore-Wilhelm at AISC 2015 Steel Conferance April 10 2015
Skidmore-Wilhelm's booth at the 2015 NASCC: The Steel Conference provided attendees a chance to learn about bolt tension and how testing fastener assemblies with a Skidmore-Wilhelm unit, such as the Model-MZ, can reduce or eliminate incorrect bolt tension in steel structures.
Our Skidmore bolt testing units were also featured in other booths to demonstrate the effectiveness of the different fastening solutions being exhibited.
Applied Bolting using a customized Model-MZ to demonstrate their DuraSquirt DTIs.
LeJeune Bolt Company using a Model-MZ to demonstrate their Tension Control Bolts.
How does bolt length affect testing? July 01 2014
A correctly installed bolt in an assembly will be flush or have up to three threads exposed from the nut.
Many sources including the Specification for Structural Joints Using High-Strength Bolts (pdf) state that flush to three threads is the proper amount of bolt stick through for a faster assembly. This specification should be followed when testing bolts since the goal is to replicate the job site faster assembly as closely as possible.
All adapters and testing units are sold by diameter so knowing what equipment is needed to test a particular bolt diameter is fairly straightforward. Bolt lengths, on the other hand, require an understanding of bolt testing equipment because there are several different solutions based on the length of a bolt.
Testing equipment related to bolt length
Short Bolt Adapters
Torque Reaction Kits
3. A torque reaction kit is required for all tightening tools with reaction arms. If your tool utilizes a torque reaction arm please use our Quote Request Form to give us the information needed to provide the correct testing solution.
Bolt length is important because it determines whether or not the bolt is considered acceptably engaged within a faster assembly. If you have any questions related to bolt length or bolt testing in general please don't hesitate to contact us and we will get you the information you need right away.
An Interview With Tim Gilles April 24 2014Tim Gilles is a teacher, author, and ASE Master Automotive Technician. He was kind enough to answer some of our questions about bolt tension and clamping force in the automotive industry.
SW Howard Website Design April 17 2014
Our website was built with the help of the Cincinnati web design agency, SW Howard Design. They deliver highly technical, beautifully designed and search engine optimized sites. They also support sites with web analytics, local marketing and social media marketing. Their timely website maintenance and goals related to increasing your bottom line make them a recommended choice for expanding your presence on the Internet. If you are interested in learning more please contact them to discuss your online presence. You can call them directly at 513-443-2794.
Torque and Tension March 14 2014
Fastener assemblies are simple machines but they are often used in very complex structures. When working in situations where joint failure is catastrophic making assumptions about how well they are working is not an acceptable method of operation. In these cases liability and refastening costs are so high that it is essential to understand the hows and whys of fastening with bolts and nuts.
It's all About Clamping Force
As you turn the nut onto the bolt, it causes the threads to press tightly against each other. As tightening continues, the desired clamping force is achieved — the nut pulling in one direction, the bolt resisting from the other.
Naturally, when the bolt and nut are this tight, resistance to further turning is very high. Your torque wrench will tell you this but it is not “torque” that determines bolt and nut tightness. It is "tension."
Tension is an indication that the length of the bolt shaft is being stretched. . . actually getting longer. You can’t see it with the naked eye, but that’s what’s happening.
If Nuts Could TalkTorque wrenches provide only part of the information you need about fastener assemblies. They tell you how much resistance they are getting from further turning of the nut. What does that resistance mean? Is the nut saying "Okay, every one of my threads is in tight contact with those on the bolt and I'm creating a tight, secure joint." Or is it saying "The rust on this bolt is catching on my threads making it hard to turn.” The dial indications may be the same for both situations so a fixed amount of torque may not always produce the same tension.
Here are some other variables that can affect torque:
- Hardness and strength of the fasteners
- Types of washers
- Thread condition
- Surface characteristics of the parts being assembled (plating, coating, hardness or smoothness)
- Improperly maintained or underpowered power tools
- Operator “feel”
Because our Skidmore-Wilhelm units test tension directly by placing the actual fastener assembly in the tester you can see the affect all the joint variables have on the amount of torque needed to produce the required tension. Using a Skidmore bolt tester in conjunction with torque wrench provides an exact torque-tension relationship.
AISC Certification March 03 2014
AISC's certification programs set the quality standard for the structural steel industry. Since their certification program focuses on error prevention rather than error correction our bolt testing units are a valuable part of the certification process. Having a Skidmore unit such as the Model MZ available during the initial evaluation and annual audits allows you to demonstrate that you understand the fundamentals of achieving proper bolt tension.
AISC certification is based on the same principle as that our calibration units were created for: even the best and experienced professionals can benefit from having procedures reviewed on a regular basis.