Author: Perry Bishop

Perry Bishop is a Technical Trainer for Columbus McKinnon Corporation.

Chain Inspection: Hoist Chain vs. Rigging Chain

Chain Inspection: Hoist Chain vs. Rigging Chain

We recently received the following question on chain inspection from Slade, a utility crew supervisor working for a water district:

“I was wondering if you carry a “no-go gauge” for Columbus McKinnon chain to inspect gouges, nicks and stretching on the links. Our warehouse personnel struggle to determine the correct gauge for your chain.”

Perry Bishop, our technical trainer, answers: 

We receive this question on chain inspection often, so we thought it would be worthwhile to write a blog to explain the gauges we offer and identify which gauge is the most suitable for the type of chain in question.

For our electric, pneumatic, hand chain hoists and lever tools, we have the following go/no-go gauge:

chain inspection
Go/no-go gauge for CM’s hoist load chain

It is made for CM’s load chain only, such as Star and Disc Grade, and should only be used to measure that style of chain. You can purchase this gauge from your local CMCO distributor under the part #3191.

To find a distributor in your area, simply visit www.cmworks.com and click on the “Find a Distributor” button on the right-hand side of the page.

For our Herc-alloy 800 & 1000 rigging chain (alloy chain slings only) we have the following wear limit rigging chain gauge, part #CWGC.  It is used to check below the hook chain such as HA-800 and HA-1000.

chain inspection
Rigging chain gauge

A common mistake that happens quite frequently in our industry is that individuals use the wrong gauge on the wrong type of chain. Always ensure you are using the correct gauge and follow instructions on the gauges for proper measuring techniques.

Perry Bishop

Perry Bishop is a Technical Trainer for Columbus McKinnon Corporation.

Will Limit Switches Work Properly if the Motor is Reverse Phased?

Will Limit Switches Work Properly if the Motor is Reverse Phased?

limit switchesJoe, an outside sales and service representative for a Columbus McKinnon distributor and recent safety webinar attendee, asks the following question about limit switches:

“Will limit switches work properly if the motor is reverse phased?”

Perry Bishop, Columbus McKinnon trainer and safety webinar presenter, answers:

When the up or down buttons are actuated, they pull in the proper contact for motor control, hence the up contactor or the down contactor. If the up or down buttons are actuated on a reverse-phased motor, the proper contact pulls in BUT the motor turns in the opposite direction.

If the up contact is in and the motor is headed in the down direction, it is going toward the lower limit switch. When the lower limit switch is activated the motor doesn’t stop because the lower contact is not controlling the motor – the upper contact is. This can lead to two problems:

1) Two-blocking, or running the chain completely out of the hoist, depending on the direction the motor is going
2) Tearing up the limit switch and possibly stripping the shaft

The UP button on the pendant should always be pushed first.

When discussing reverse phasing, it is critical that all customers (and installers) know that when activating the hoist for the first time, the UP button on the pendant should always be pushed first. By doing this, if the hoist is reverse phased, the hook will lower revealing that the motor leads are wired incorrectly. If the motor is phased properly, the hook will raise and the limits will function properly. Either way the potential for “two-blocking” is avoided.

In conclusion, limit switches will not work properly if a motor is reverse phased.

Want to learn more? View our Safety Webinar on “Understanding Hoist Control Circuits.”

This blog post was updated on 10/22/2015 with additional content.

Perry Bishop

Perry Bishop is a Technical Trainer for Columbus McKinnon Corporation.

Can hoist hooks be repaired?

Can hoist hooks be repaired?

LodestarHook During my training sessions, I am frequently asked if hoist hooks can be repaired if they are damaged or broken. OSHA and ASME regulations provide specific requirements for hoist hook repair to help answer this question.

According to OSHA 1910.179 (L)(3)(iii)(A), hook repairs by welding or reshaping are not generally recommended. If such repairs are attempted they shall be done under competent supervision and the hook shall be load tested before further use.

While OSHA 1910.179 specifically pertains to a crane with top-running girders and top-running trolleys, it states that hook repair is allowed under certain conditions.

On the other hand, ASME B-30.10 Section 10-1.3 (d) states that “attachments, such as handles, latch supports, etc. shall not be welded to a finished hook in field applications. If welding of an attachment such as these is required, it shall be done in manufacturing or fabrication prior to any required final heat treatment.”

So the question remains, can hoist hooks be repaired?

Typically hoist hooks are forgings processed from hot-rolled alloy steel blanks of medium carbon content, such as grade AISI 4140. Hooks can be used in the “as forged” condition or further enhanced by thermal processing (heat treatment). Although fatigue strength improves with heat treatment, there is a resulting loss of ductility and elongation.

A repair that involves welding or any kind of heat treatment can affect the strength and ratings of a hook and therefore is not recommended.

Keep in mind, when a hook is damaged or broken, it can be an indicator that the hoist was overloaded, in which case the entire unit should be inspected for other damages.

In addition to referencing OSHA and ANSI requirements for hook repair, we also recommend that you always contact the manufacturer before making any questionable repairs on their products.

For more information on this topic, check out our Pre-operational Hoist Inspection video.

Further your education on crane and hoist operation and inspection. Check out these upcoming training courses from Columbus McKinnon:

Overhead Crane and Hoist Inspection Certification
CMCO Chain/Wire Rope Hoist Technician Certification

What other hoist or rigging questions do you have?

Perry Bishop

Perry Bishop is a Technical Trainer for Columbus McKinnon Corporation.