About Us Brands Download Contact Counter Sales FAQ Freight Payments Products Search Site Technical More Links...

Pitch - Glossary - Technical

Glossary - Pitch

The pitch circle is an imaginary circle on a gear, pulley or similar mechanical device that divides the teeth at the optimal contact point. The optimal contact point is where two gears or a belt and pully contact each other when in correct mesh. The pitch is the distance from center to center of any two adjacent teeth of a gear, toothed belt, sprocket, toothed pulley or similar mechanical device as measured along the pitch circle. Pitch diameter is the diameter of the pitch circle.

Pitch is also used to describe the distance between threads of a screw, ballscrew or acme thread. It can also describe the centre distance between holes in a predrilled item such as shafting, rails or gear racks.

Timing belt and pulley pitches are usually specified as the distance between the teeth in mm.

For gears, metric pitch uses the module designation. If you divide the pitch circle diameter of a metric spur gear by the number of teeth you arrive at the module. A spur gear of module 1.0 will have a pitch circle diameter (PD) equivalent to the number of teeth eg, module 1 with 25 teeth = 25mm pitch circle diameter. A Spur gear with a module of 0.8 will have a pitch circle diameter equivalent to 0.8 times the number of teeth eg; module 0.8 with 25 teeth = 20mm pitch circle diameter.

Imperial sized spur gears use the American Standard DP (Diametrical Pitch) numbering system eg 16DP, 24DP, 32DP. To arrive at the DP for imperial sized spur gears you divide the number of teeth by the pitch diameter in inches. A 16DP gear with 16 teeth will have a 1 (25.4mm) pitch diameter and a 32DP gear with 16 teeth will have 1/2" (12.7mm) pitch diameter.

The pitch diameter is the diameter across the gear from half way between the top and the base of the tooth. So for a module 1 metric spur gear with 50 teeth, the pitch diameter will be 50mm, but the overall diameter of the gear across the teeth will be 51mm (pitch diameter + the module) and the diameter fron the base of the teeth on one side to the base on the opposite side will be 49mm.

Technical Index Glossary Index

You can find many types of transmission products in the Hobby and Engineering Supplies Transmission Online Catalogue pages.

For a huge range of bearings online please visit the Bearing Shop Online Website.

The Small Parts and Bearings has a much larger range of engineering supplies.

For the best range of miniature and small bearings please try the Miniature Bearings Australia website. Miniature Bearings Australia also list a large variety of miniature engineering products.

Other pages related to Technical - Glossary

Click Page Banner Below


Other Technical Pages

Click Page Banner Below


Main Pages

Click Page Banner Below




Accessories Adhesives Allthread Balls Balsa Bar Batteries Bearings Automotive Bearings Mounted Bearings for Housings Books Bottles and Cans Brushless Motor Be... Bushes Bronze Bushes Steel Carburettor Parts Castors Circlips Cloth Clutches Collars Collectibles Dental Handpiece P... Disk Cleaning Machine Dubro Accessories Educational Projects Electrical Wire Engineering and Ho... Fishing Reel Parts Foam Food Processor Parts Framing Fuel Gadgets Games Amusement Games General Gearbox Parts Gearmotors Basic Hobby Accessories

Paypal Accepted
Secure Checkout

Hobby Gears Hobby Motors Hobby Servo Motors Hobby Shafting Hobby Wheels Jigsaws Jockey Wheel Thrus... Kites Knobs Pointer Leads and Connectors Lifting Chain Lights Lubricants General... MRI Table Bearings Magnets Bar Model Car Kits Model Personnel Model Planes and H... Modelling Accessories Modelling Paints Nuts Nuts Lock Oil Seals Oils Specialised Parts Boxes Plastic Plungers Ball Plywood Power Adaptors Power Tool Parts Pulleys Grooved Pushbike Bearings RC Aircraft Parts RC Bike Parts RC Boat Parts RC Boats and Acces... RC Car Parts RC Engine Parts RC Filters RC Helicopter Parts

Visa Card Accepted
Secure Checkout

RC Nitro Accessories RC Nitro Engine Ac... RC Nitro Engine Parts RC Propellers and ... RC Quadcopter Parts Radio Equipment Robotic Bases Robotic Servo Motors Rod Ends Screws Screws Button Head Screws Cap Head Screws Cheese Head Screws Countersunk Screws Hex Head Screws Large Head Screws Pan Head Screws Round Head Screws Security Screws Self Tapping Seals and Sealing Sets Sheet Shim Shock Absorbers Soldering Spacers Spare Parts Special Effects Li... Speed Controllers Spinners Sporting Spray Paint Springs Extension Stationery Surplus Stock Swimming Pool Bear... Switches Tape Threaded Rod

Master Card Accepted
Secure Checkout

Throwing Planes Timing Belts and P... Timing Belts and P... Timing Belts and P... Tools Bits Tools Cutting Tools General Purpose Tools Pullers Tools Screw Drivers Tools Threading Tube and Tubing Vacuum Cleaner Belts Washers Finishing Wheels RC Plane Wheels and Tyres R...

Site Summary

Freight Rates
Terms and Conditions
Privacy Policy

Hobby and Engineering Supplies offers 2531 products in 281 categories including spare parts for remote control cars, assortment kits, kites, styrene, depron, ceramic and ceramic hybrid bearings, bearings, tools, belts and adhesives - see the full listing in the Online Catalogue. We have excellent Freight Rates within Australia and worldwide. We offer a choice of delivery with a signature required, or cheaper options with no signature required. The no signature required options are at the customer’s risk once the goods leave our store.

Using the links throughout this site you will find extensive information including catalogues, technical data, and other product specific information. We sell our products worldwide through our online store and our overseas freight rates are competitive for fully traceable courier delivery.

Hobby and Engineering Supplies is part of MBA Group offering a select range from the MBA Group catalogue.

Hobby and Engineering Supplies products are not authorised for sale into the USA or Canada due to the reluctance of Australian insurers to provide product liability insurance into those two countries.

Information on this website is Copyright Hobby and Engineering Supplies 1997. All rights reserved.