17 - Skate - Hobby
Skate Bearings - Question 17
What is the meaning of "Z" and "ZZ" in the bearing code?
Most brands use the designation "Z" to mean a steel shield covering the side of the bearing. "ZZ" simply means that the bearing has a shield on both sides. Normally, the shield itself will be branded as "608 Z" even though there is a shield on both sides of the bearing. This is for practicality in manufacturing. It is much more economical to produce all of the shields stamped as "608 Z" than it would be to manufacture the exact same component with "608 ZZ" stamped on the ones to be used for bearings with two shields. Some manufacturers supply bearings with removable shields, whilst others have shields that are crimped in place. Neither is usually better than the other unless you intend replacing the lubricant or cleaning the bearing from time to time (neither of which is recommended by the manufacturer).
You can purchase online at Bearing Shop Online.
The Small Parts and Bearings website has a much larger range of engineering supplies.
Hobby and Engineering Supplies lists a smaller range of products and only the most popular items in each range. They also list many additional hobby specific categories.
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.
Extra information for Hobby - Skate
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Bearing Shop Online offers 25871 products in 532 categories including ball bearings, roller bearings, thrust bearings, ceramic and ceramic hybrid bearings, stainless steel bearings, miniature bearings, linear bearings, shafting, corrosion resistant - 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.
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