Technical Corner Questions & Answers
How should you count the number of pitch in a strand of roller chain?
While “one at a time” and “correctly” seemed to be the most frequent—and apparently most amusing—answers from our engineering team, after some consideration we thought this deserved an answer that was a bit more practical.
One mistake commonly made when counting the number of pitches in a strand of roller chain is to include only exterior link plates. By counting only the exterior plates, only half the number of pitches end up being counted.
So then, how should the number of pitches be counted? Taking a quick time out for a review of definitions—the pitch of a roller chain is the distance between the center of one pin to the center of the next pin. To count the number of pitches in a strand of chain, we would start our count from the first pin on one end of the piece of chain and move to the next pin, which would be one pitch, and then on to the next pin, which would be another pitch, and so on until the end of the strand of chain is reached.
Here’s a quick visual to help illustrate:
Have additional questions about counting the number of pitch in a strand of chain? Send us an email email@example.com. For more information on the maintenance and installation of roller chain, check out our maintenance guide.
Someone threw me a curveball, how do I convert pitch to feet?
To answer this question, let’s do a quick refresher on the ANSI part numbering system. The first digit(s) in each standard roller chain part number tells us the pitch of a chain in eighths of an inch. That means that an ANSI 120 chain, for example, has a pitch of 12/8s of an inch or 1.5 inches.
Let’s say then that we wanted to know how many feet of chain are in an application of ANSI 120 that is 180 pitches in length?
Again, we know that ANSI 120 chain has a pitch of 1.5″. For an application with 180 pitch, we simply multiply 1.5 inches by 180 to get 270 inches or convert to feet 270/12 = 22.5.
But what if we want to convert from feet into pitch? Let’s say we have an application that uses 10 feet of ANSI 40 chain. We know from the ANSI numbering system that ANSI 40 chain has a pitch of 4/8s of an inch or .5 inches. For an application of ten feet, we do a quick conversion from feet into inches (10 x 12 = 120) and then divide 120/0.5 to get 240 pitches.
Knowing how to convert between pitch and feet can be useful, especially when double checking an order, but don’t worry if you need additional help. Diamond Chain’s customer service and application engineering teams [link to contact page] are available to assist you.
Have additional questions about converting pitch to feet and vice versa? Send us an email firstname.lastname@example.org or give us a call. To find an authorized dealer in your area that can assist with cut-to-length orders, please check our distributor finder.
What is “working load” and what role does it play in selecting roller chain?
To start, we should clarify that working load, also known as chain pull, and tensile strength are not the same. Working load describes the amount of linear pull exerted on a chain by a drive while tensile strength is the amount of force required for that chain to fail. While these measurements can be related, the two terms are not interchangeable.
For drives operating at speeds lower than those shown in Diamond’s horsepower ratings charts, chain pull, in combination with tensile strength, can be used to select the appropriate roller chain. Here are several equations used to determine working load or chain pull:
Generally, chain pull should not exceed 1/6th of the ultimate, or maximum, tensile strength for chain with press-fit connecting links or non-offset links or 1/9th of the maximum for slip-fit connecting links or offset links. By comparing chain pull against rated tensile strength, the appropriate chain can be selected.
Have more questions about working load? Drop us a note!
Ask the Engineer Questions & Answers
Why does Diamond’s maintenance-free DURALUBE chain ship with additional external lubricant?
Although DURALUBE’s sintered bushing and rollers have lubricant drawn in under vacuum, the additional external lubricant applied prior to shipping provides additional protection for the roller chain. In addition to providing overall lubrication that will maximize the service life of the chain, the proprietary Diamond Chain lubricant is also a rust preventative in case the chain is not used immediately.
Our operation requires a daily cleaning that includes bleach, alcohol, and water. What type of chain would you suggest for this type of operating environment?
For this application, we recommend using Diamond’s AP Series stainless steel chain. The AP Series uses austenitic stainless steel, which is ideal for food processing applications and is approved by the FDA. This grade of stainless steel features total resistance to corrosion from alcohol and strong resistance to corrosion from bleach, or sodium hypochlorite.
For additional information on the corrosion resistance of different types of stainless steel substrates, you can check out our Corrosion and Special Finish product guide.
What is oval contour chain and how is it different from standard ANSI chain?
Diamond’s oval contour roller chains feature a different link plate from Diamond’s standard ANSI series chain. Unlike Diamond’s standard figure-eight-style link plate, the oval contour plates take their name from their oval shape. Oval contour roller chain is designed for high load applications. These chains are manufactured using a medium carbon alloy steel that is through-hardened to deliver a higher working load capacity. In addition, the rigidity of the link plates is ideal for high load applications that may cause fatigue failures.
What are the differences between 50, 50 1R, and 50 2R roller chain?
The “50” in the part number refers to ANSI size 50 roller chain. The “R” refers to riveted chain construction. Riveted chains use a sidemash on the pins to hold the link plates in place instead of a cotter pin or spring clip. The extra digit refers to the number of strands. 50 and 50 1R are both single-strand chains while the 50 2R is a double-strand chain.
Diamond chains sometimes seem like they are over-lubed compared to other chain manufacturers. Why is that?
Diamond Chain is always working to maximize roller chain service life. We know from both our history and our product tests that proper lubrication is vital. The challenge is to deliver the right amount of lubrication for very different customers.
Some of our customers will install chain soon after they receive it while others may wait days, weeks, or months. Some customers might subject their chain to outdoor, corrosive, or caustic working conditions. Our manufacturing team works very hard to ensure that no matter when, where, and how our chain ends up being used, it is properly lubricated, corrosion free, and ready to go.
Should you need a chain with more or less lubricant, just let your district manager or customer service representative know when placing your order.
Should DURALUBE series chain be lubricated after it is installed?
Although DURALUBE is Diamond’s maintenance-free roller chain, anytime you have the opportunity, or ability, to lubricate roller chain, you should. Additional lubrication is beneficial and can significantly extend the life of any roller chain, even if it’s maintenance-free chain.
Does Heavy Series chain require different sprockets?
While single-strand Heavy Series roller chain does not require different sprockets, multi-strand Heavy Series chain does as the thicker plates make the width between the strands of chain wider. This means that the centerline of the sprocket teeth needs to be farther apart.
Does double-pitch roller chain require different sprockets?
The answer depends on the sprocket. For sprockets with 30 or more teeth, the answer is no. For sprockets with less than 30 teeth, a sprocket designed for double-pitch chain is necessary.
We do recommend that a sprocket with an odd number of teeth be used. That way, the extended pitch chain will skip every other sprocket tooth, engaging every other cycle. This is an easy way to reduce wear by reducing the frequency of contact between the chain and the sprocket.
Is there a proper way to store roller chain when it’s not being used? We use ANSI 50 and 60 roller chain on a fertilizer roller for about three weeks out of the year. We’ve been removing the chain and storing it in diesel fuel, but the links are starting to get stiff.
When a chain is only used for a few weeks throughout a year, you can extend the life of the chain by removing it, cleaning it, and prepping it for storage.
Diesel fuel and kerosene are good options for cleaning roller chain. We would advise you to agitate the chain while it’s submerged in order to remove any debris that might be stuck in an interior joint. Let the chain air dry and place it in a medium to heavy weight oil. This will help protect the chain while in storage and ensure that it’s ready to go for the next year.
How does Diamond Chain mark the links on their products? I want to make sure I’m getting “the real McCoy” and not an inferior chain.
Diamond Chain uses three distinct product marks to differentiate between its Diamond, Infinity, and Sapphire product series. Diamond Chain’s flagship Diamond series includes a stamp of the words “Diamond Chain” along with the Diamond graphic element. The Infinity series includes only the Diamond graphic element stamp while Sapphire has a RSC stamp for Sapphire roller chain.
In order to guarantee that you are purchasing authentic Diamond Chain products, you should always buy from an authorized Diamond distributor. For help locating an authorized distributor, you can use our distributor locator for North American customers or European customers.
In the late 1940s, Harley Davidson made a lightweight 2 stroke motorcycle that used Diamond #35 chain in the front and #40 in the rear. What was the last year that Diamond Chain manufactured this bi-color (blue inner links and gray outer plates) #40 roller chain?
A – Diamond Chain discontinued the use of the “bluing” process for the production of inner plates for standard #35 and #40 roller chains in 1987. Although still a process in use today as a means of passive rust protection, Diamond Chain discontinued the use of the bluing process in favor of more effective means of rust protection including Diamond’s proprietary lubricant formulation.