CeramicAngular Contactbearings

Click on INFO in the rows below to display technical drawings of the bearings with load and speed data. Please note that the maximum loads and speeds are used in theoretical life calculations. It is recommended to use bearings at significantly less than the maximum load and speed ratings to ensure reasonable bearing life. ZrO2 full ceramic bearings are best used at low speeds. For higher speeds or continuous rotation over long periods, they will perform better with Si3N4 balls. For further information contact sales@smbbearings.com.

The inch-sized ZrO2 full ceramic ball bearings listed below are available with cages (or retainers) made from PEEK or PTFE. Bearings with bore sizes from 8mm upwards can also be fitted with 316 stainless steel cages. In addition, we keep stock of full complement ZrO2 bearings. These have no cage and extra balls. For full complement type, the load ratings are approximately 20% higher but the maximum speed is up to 70% lower. As for bearing cages, PEEK is generally the preferred option from stock due to the strength and durability of PEEK. If an alternative cage material is required to cope with particular chemicals or temperature extremes beyond the range of PEEK, these can be manufactured to order. Inch-sized ZrO2 bearings are not magnetic or conductive and they are highly corrosion resistant to most chemicals. They are also extremely water resistant which is why they are often used in marine applications, particularly where the equipment is fully submerged or where 316 marine grade bearings will not cope with the load or speed. It is important to note that if ZrO2 has prolonged contact with steam or hot water, there may be some weakening of the material over time.

Full complement ZrO2 imperial bearings or those with a 316 stainless cage can be used up to 600°C. The maximum speed should be decreased as the temperature increases above ambient, particularly if the bearings are unlubricated. Bearings with a PEEK cage are rated up to 250°C due to the lower maximum temperature of the cage material. It may be preferable to use a looser radial play at high temperatures, particularly if the inner ring temperature is likely to be greater than the outer ring temperature as this will reduce the radial play of the bearing. Our ZrO2 imperial bearings are supplied with a looser C3 radial play as standard.

Ceramic bearings

THEREFORE THERE IS NO LEGAL BASIS FOR REIMBURSING THE APPROPRIATION OF THE BUREAU OF FOREIGN AND DOMESTIC COMMERCE FOR EXPENSES AND OBLIGATIONS OTHERWISE PROPERLY INCURRED PRIOR TO SEPTEMBER 27. 1951: REFERENCE IS MADE TO YOUR LETTER OF NOVEMBER 8. REQUESTING A DECISION AS TO WHETHER YOU ARE AUTHORIZED TO CERTIFY FOR PAYMENT BUREAU VOUCHER NO. 1 2829. ON WHICH IT IS PROPOSED TO REIMBURSE THE APPROPRIATION " SALARIES AND EXPENSES. IN YOUR LETTER IT IS STATED. WHICH DATES ARE THE DATES OF APPROVAL OF THE DEFENSE PRODUCTION ACT OF 1950 ( PUBLIC LAW 774) AND THE SUPPLEMENTAL APPROPRIATION ACT. CERTAIN FUNCTIONS WERE DELEGATED TO THE DEPARTMENT OF COMMERCE PURSUANT TO THE SAID DEFENSE PRODUCTION ACT OF 1950 BUT THAT.

APPROPRIATIONS - BUREAU OF FOREIGN AND DOMESTIC COMMERCE - REIMBURSEMENT FOR DEFENSE PRODUCTION OBLIGATIONS INCURRED PRIOR TO DEFENSE PRODUCTION APPROPRIATION THE ACT OF SEPTEMBER 27, 1950, APPROPRIATING FUNDS FOR THE PAYMENT OF OBLIGATIONS INCURRED PURSUANT TO THE DEFENSE PRODUCTION ACT OF 1950 CONTAINS NO AUTHORITY FOR THE PAYMENT OF EXPENSES OF DEFENSE PRODUCTION INCURRED PRIOR TO SEPTEMBER 27, 1950, OR FOR THE TRANSFER OF ANY FUNDS FOR THE PURPOSE OF REIMBURSING APPROPRIATIONS FOR OBLIGATIONS AND EXPENSES SO INCURRED, AND THEREFORE THERE IS NO LEGAL BASIS FOR REIMBURSING THE APPROPRIATION OF THE BUREAU OF FOREIGN AND DOMESTIC COMMERCE FOR EXPENSES AND OBLIGATIONS OTHERWISE PROPERLY INCURRED PRIOR TO SEPTEMBER 27, 1950, IN THE PERFORMANCE OF ADDITIONAL DEFENSE PRODUCTION FUNCTIONS IMPOSED UPON THAT BUREAU BY EXECUTIVE ORDER.

FOR EXPENSES NECESSARY TO ENABLE THE PRESIDENT TO CARRY OUT THE PROVISIONS OF THE DEFENSE PRODUCTION ACT OF 1950 ( PUBLIC LAW 774), APPROVED SEPTEMBER 8, 1950 * * * $30,000,000.

Ceramicbearing manufacturers

ACCORDINGLY, THE VOUCHER TRANSMITTED WITH YOUR LETTER MAY NOT BE CERTIFIED FOR PAYMENT AND SAID VOUCHER WILL BE RETAINED IN THE FILES OF THIS OFFICE.

REFERENCE IS MADE TO YOUR LETTER OF NOVEMBER 8, 1950, FILE AS, REQUESTING A DECISION AS TO WHETHER YOU ARE AUTHORIZED TO CERTIFY FOR PAYMENT BUREAU VOUCHER NO. 1 2829, THEREWITH SUBMITTED, ON WHICH IT IS PROPOSED TO REIMBURSE THE APPROPRIATION " SALARIES AND EXPENSES, BUREAU OF FOREIGN AND DOMESTIC COMMERCE, 1951," FROM THE APPROPRIATION " EXPENSES, DEFENSE PRODUCTION, EXECUTIVE OFFICE OF THE PRESIDENT, 1951," IN THE AMOUNT OF $8,609.98 DISBURSED FOR PURPOSES OF DEFENSE PRODUCTION.

HybridCeramicwheelBearings

FullCeramic bearings

Although PEEK is very durable, it will become more brittle at low temperatures so it is worth considering PTFE or 316 stainless steel cages for temperatures below -70°C. For an overview of the pros and cons of using ZrO2 bearings, you can click HERE to see a helpful guide on selecting ceramic bearings.

Most of the range of inch sized ZrO2 ceramic bearings are supplied from stock in the UK. We also supply full ceramic imperial bearings from stock in silicon nitride. See Products Variants below for the Si3N4 versions.

Zirconium dioxide bearings have high hardness, very smooth wear surfaces and can run without lubrication so they are frequently used where very low turning resistance is important. They have a very low coefficient of friction compared to steel bearings or even hybrid bearings. The coefficient of friction for ZrO2 bearings at ambient temperature in air with a light load is approximately 0.0012.

IN YOUR LETTER IT IS STATED, IN SUBSTANCE, THAT THE SAID VOUCHER COVERS EXPENSES INCURRED DURING THE PERIOD FROM SEPTEMBER 8 TO SEPTEMBER 27, 1950, WHICH DATES ARE THE DATES OF APPROVAL OF THE DEFENSE PRODUCTION ACT OF 1950 ( PUBLIC LAW 774) AND THE SUPPLEMENTAL APPROPRIATION ACT, 1951 ( PUBLIC LAW 843), RESPECTIVELY; THAT, BY EXECUTIVE ORDER NO. 10161 DATED SEPTEMBER 9, 1950, CERTAIN FUNCTIONS WERE DELEGATED TO THE DEPARTMENT OF COMMERCE PURSUANT TO THE SAID DEFENSE PRODUCTION ACT OF 1950 BUT THAT, SINCE NO APPROPRIATIONS TO CARRY OUT THE PURPOSES OF THE SAID ACT HAD BEEN MADE AT THAT TIME, AND DUE TO THE EMERGENCY NATURE OF THE DEFENSE PRODUCTION PLANS, THE BUREAU OF THE BUDGET INFORMALLY APPROVED A SPECIAL ALLOTMENT (225) UNDER THE ABOVE-MENTIONED APPROPRIATION " SALARIES AND EXPENSES, BUREAU OF FOREIGN AND DOMESTIC COMMERCE, 1951," FOR THE PURPOSE OF ,TEMPORARILY CHARGING TRANSACTIONS INCIDENT TO DEFENSE PRODUCTION, PENDING THE AVAILABILITY OF FUNDS.'

Our determination to remain specialised gives us a high level of product knowledge, providing bearing and lubrication solutions to existing or potential customers, whether individuals or large corporations. We don’t just sell bearings, we help to solve your problems. - Chris Johnson, managing director of SMB Bearings.

THE LAW ( PUBLIC 843, 64 STAT. 1054) MAKING THE SAID APPROPRIATION CONTAINS NO PROVISION THAT FUNDS APPROPRIATED THEREIN WILL BE AVAILABLE FOR THE PAYMENT OF OBLIGATIONS INCURRED DURING THE PERIOD SEPTEMBER 8, 1950, THE DATE ON WHICH THE DEFENSE PRODUCTION ACT OF 1950 ( PUBLIC LAW 774, 64 STAT. 798) WAS APPROVED, TO SEPTEMBER 27, 1950, THE DATE OF THE APPROVAL OF PUBLIC LAW 843. MOREOVER, THE SAID APPROPRIATION ACT DOES NOT AUTHORIZE THE TRANSFER OF ANY FUNDS APPROPRIATED THEREBY FOR THE PURPOSE OF REIMBURSING APPROPRIATIONS CHARGED WITH OBLIGATIONS AND EXPENSES INCURRED PRIOR TO SEPTEMBER 27, 1950. CONSEQUENTLY, AND AS THE APPROPRIATION " SALARIES AND EXPENSES, BUREAU OF FOREIGN AND DOMESTIC COMMERCE" WAS AVAILABLE FOR AND PROPERLY CHARGED WITH OBLIGATIONS INCURRED IN THE PERFORMANCE OF THE ADDITIONAL FUNCTIONS IMPOSED UPON THE DEPARTMENT OF COMMERCE BY EXECUTIVE ORDER NO. 10161 (SEE 15 COMP. GEN. 167), THERE IS NO LEGAL BASIS FOR THE PROPOSED TRANSFER OF FUNDS.

ZrO2 or zirconium dioxide is a tough ceramic material with very similar expansion properties to steel. This is an advantage when considering shaft and housing fits for higher temperature applications. Although we usually refer to these bearings as ZrO2 bearings, they are made from ZrO2 stabilised with yttrium oxide which gives the material added strength and increased fracture resistance at room temperature. This is sometimes known as YSZ or YTZP. ZrO2 bearings are roughly 70% of the weight of steel bearings.