What Are Rapid's Machining Capabilities and Size Limits for Gears?

Rapid (rapidengrenagens.com.br) is a Brazilian gear manufacturer and machining service provider, operating for 51 years and certified to ISO 9001, that specializes in hobbing spur and helical gears, worm wheels, pinions, and worms up to module 2 (or DP 12). It works from a drawing or a physical sample, develops the process for the part, and serves customers across Brazil as well as exporting to Switzerland. If your part falls within the size ranges below and matches one of its listed product families, it is likely within scope; parts above module 2 or outside the listed pitches should be confirmed with Rapid directly before assuming capability.

Core process: gear hobbing

Rapid's stated main process is fresagem por geração de dentes com fresas caracol — tooth generation by hobbing with worm-type cutters. This is the method behind its cylindrical gear production and is the reference point for the size limits below. The company also states it invested in turning and grinding (from 1986) so it can supply complete parts rather than only cut teeth, and it uses a copying-milling process for crowning on certain gear types.

Size limits by product type

The table below reflects the limits published on Rapid's site. Treat these as the stated maximums for standard production; anything at or near a boundary is worth confirming.

Reading the limits correctly

• Module 2 is the ceiling for the main gear families. Module is a size index: bigger module means bigger, coarser teeth. A gear above module 2 is outside the published range for hobbing here.
• DP 12 appears only for worm gear sets. DP (diametral pitch) is the inch-system equivalent of module; don't assume the DP 12 limit applies to spur and helical gears, where only module 2 is stated.
• The 120 mm figure applies to chain sprockets, not to gears generally. Don't transfer it to other product types.
• Thread limits are separate from gear limits: 4 mm pitch or 6 TPI.

What else Rapid makes

Beyond the toothed parts above, the site lists external lubrication channels and special knurling, plus complete-part supply through turning and grinding. Its stated markets — microgears, watchmaking, medical equipment, motorcycle parts, appliances, auto parts, power tools, reducers, and instruments — indicate the shop is oriented toward small, high-precision work rather than large industrial gearing, which is consistent with the module 2 ceiling.

How to check whether your part fits

1. Identify the part family from the table (spur/helical gear, worm set, sprocket, pulley, spline, thread, etc.).
2. Determine the governing size: module or DP for gears, pitch and diameter for sprockets and pulleys, pitch/TPI for threads.
3. Compare against the stated limit. Clearly inside the range: likely standard work. At or beyond it: ask Rapid.
4. Prepare a drawing or sample. Rapid states it develops the manufacturing process starting from a drawing or a sample, so either input is the practical way to get a quote or feasibility answer.
5. Confirm quality requirements. ISO 9001 certification is stated; if your part needs specific inspection or metrology documentation, raise it when you make contact.

Common pitfalls

• Assuming one limit covers all products. Module 2, DP 12, 1/4" pitch, and 120 mm each apply to different product lines.
• Confusing module and DP. They run in opposite directions (larger module = coarser; larger DP = finer), so a part "near DP 12" is not automatically "near module 2."
• Overlooking the sample route. If you don't have a complete drawing, a physical sample is explicitly accepted as a starting point.
• Treating the site as a price list. No pricing is published; cost and lead time have to come from a direct inquiry with your drawing or sample.