Martin Sprocket and Gear Inc. FAQ: Suppliers, Louis V Belt, AC Motor Speed Control, and Bevel Gears

Most of the questions I get from maintenance and engineering teams have the same starting point: they're trying to source a component without getting burned. I'm a quality/compliance manager at an industrial transmission distributor. I review roughly 200 unique part numbers a year - sprockets, gears, belts, motors, the works - and I rejected about 6% of first deliveries in 2024 for missing certifications or incorrect heat-treat marks.

Here are the questions that show up in our support queue the most, answered the way I'd answer them over the phone.

• What exactly does Martin Sprocket and Gear Inc. make?
• How do I find Martin Sprocket and Gear suppliers I can trust?
• Is a Martin sprocket always better than a generic one?
• What is a 'Louis V belt'?
• How does AC motor speed control work with sprockets and belts?
• What uses a bevel gear?
• What should I check on delivery before accepting Martin parts?
• Is buying Martin Sprocket and Gear online actually faster?

What exactly does Martin Sprocket and Gear Inc. make?

Not just sprockets. The full company name is Martin Sprocket and Gear Inc., and the gear part of the name is literal. The company manufactures power transmission and material handling components: sprockets and roller chain, gears and bevel gears, sheaves and V-belt drives, bushings, couplings, bearings, conveyor components, and motors and reducers. Their catalog also covers hand tools and drive accessories.

If you search for 'Martin Sprocket' only, you're probably looking for a sprocket. But it's worth checking the full Martin Sprocket and Gear Inc. catalog. A machine might need a sheave or a V-belt even when the original trouble ticket says 'sprocket.'

How do I find Martin Sprocket and Gear suppliers I can trust?

That's the question I get the most. 'Martin Sprocket and Gear suppliers' can be a local distributor, a national motion-control house, or an online seller with three product photos and a contact button.

Here's the thing: the seller's website matters less than the source. Ask for the manufacturer's part number and a source lot number. A genuine Martin Sprocket and Gear Inc. part has a product number and batch traceability. If the seller says 'equivalent to Martin', that's a red flag. Equivalent isn't interchangeable.

I'm not 100% sure every online seller who claims 'genuine Martin' is wrong. But the question is still worth asking.

Is a Martin sprocket always better than a generic one?

Not always. 'Better' depends on the application. For a food-processing conveyor running 16 hours a day, I'd want a Martin sprocket, preferably stainless or with material certification. For a slow-moving repair part in a low-duty gate, a generic part can work, if you inspect it.

When I compared a genuine Martin sprocket and an import copy side by side, the tooth profile looked identical at a glance. Then we measured the pitch: the copy was off by 0.012 inch across five teeth, enough to make a chain bind on one side. That was the moment I stopped judging parts visually.

So no, it's not always better. But it's more likely to be right, and in power transmission, 'right' is cheap at almost any price.

What is a 'Louis V belt'?

I had to look this one up when I started seeing it in search reports. My best guess is that 'louis v belt' comes from someone trying to find a replacement V-belt for a Louis Allis motor. Louis Allis is a name you'll find on industrial motors and generators. The belt itself isn't a proprietary 'Louis' product. It's a standard industrial V-belt section, like A, B, or C, sized for the drive's center distance.

If you're replacing a belt on a Louis Allis motor, match the section and length to the original drive. A V-belt from Martin Sprocket and Gear Inc. is a common replacement. Don't hold me to every exception, but you don't need to order it from the motor manufacturer.

How does AC motor speed control work with sprockets and belts?

In most industrial setups, AC motor speed control comes from a variable frequency drive, or VFD. The VFD changes the frequency and voltage going to the motor, which changes the motor speed. Instead of a fixed 1,800 rpm motor, you can run at 900, 1,200, or anywhere in between, within the motor's design range.

But you can also control output speed mechanically. Change the sprocket or sheave ratio and you change the driven speed at a fixed motor speed. That's less flexible, but it's repeatable and usually simpler to maintain. I've seen plants use a VFD when they need a range of speeds and a carefully sized sprocket drive for the standard operating point. Both are valid.

From a quality standpoint, a VFD is an efficiency upgrade because it gives you data on current, torque, and run hours. But if the machine only needs to run at one speed, a well-matched sprocket and belt drive is hard to beat. The efficiency win comes from fewer moving parts and less downtime.

What uses a bevel gear?

Anything that changes the direction of power between two intersecting shafts. The classic example is a vehicle differential, but you also see bevel gears in hand drills, angle grinders, mixers, printing presses, conveyors, and right-angle pump drives.

Suppose you have a vertical motor and you need to drive a horizontal conveyor shaft. A bevel gear set makes that 90-degree turn with a positive, fixed ratio. Miter gears are the same idea, except they always run at a 1:1 ratio. If you ask a supplier for a bevel gear when you really need a miter gear, you'll get a follow-up question or two. Now you'll know why.

So if you're searching 'what uses a bevel gear', look at the shaft angle and the ratio in front of you. That will tell you exactly which gear to order.

What should I check on delivery before accepting Martin parts?

Start with the label. Does the part number on the box match the part number on the purchase order? That sounds obvious, but I've rejected more orders for wrong part numbers than for wrong parts.

Then check the physical part: bore size, keyway, set screws, tooth profile, and heat-treat marks. If a sprocket is supposed to be induction-hardened, there should be a visible hardness pattern. No mark isn't automatically a defect, but it raises questions.

The best time to catch a bad part is before it leaves the box.

Lot numbers matter too. A genuine Martin Sprocket and Gear Inc. part should have enough traceability on the box to identify the production lot. Keep that record. Once the part leaves the box, you lose the easiest proof.

It took me about three years and a $22,000 redo to understand that receiving inspection isn't just for large orders. We didn't have a formal gate for small orders. Now every order gets the same label-to-part check. A single cheap sprocket can shut down a line just as fast as an expensive gearbox. Check the part while the supplier is still accountable. Not ideal, but better than the alternative.

Is buying Martin Sprocket and Gear online actually faster?

Usually, yes, but compare the whole process, not just the price. A good online catalog shows availability, part numbers, and lead times before you call. That alone cuts the back-and-forth. In 2024, our digitally sourced orders had fewer specification errors than phone and fax orders because there was a written record of every choice.

The total cost isn't just the list price. Shipping, rush fees, and a wrong part can wipe out any savings. If a supplier's website lets you filter by bore size and keyway, you're less likely to get a mismatch. That's the kind of efficiency I care about.

Switching our preferred supplier portal cut our average inquiry-to-order time from two days to about four hours. The parts weren't cheaper. The process was faster.