Plaig Bearing Specifications (Materials and Precision Ratings)

Standard Bearing Specifications

ABEC 3 Rated Chrome Steel Rings, balls & retainer, PTFE Rubber seals or Chrome steel metal shields. (Bearing Materials and Precision Ratings Listed Below)

Premium Bearing Specifications

ABEC 5 Rated Chrome Steel Rings, Balls & Retainer, PTFE Rubber Seals or Chrome Steel Metal Shields. Some Premium Bearings have PA46 Retainer in larger sizes.

V2 Premium Bearing Specifications

ABEC 7 Rated Chrome Steel Rings, Balls & Retainer, PTFE Rubber seals or Chrome Steel Metal Shields. Made to the highest spec available to us.

Ceramic Bearing Specifications

Specs vary greatly depending on size, all larger bearings over 10mm inner diameter are ABEC 5, smaller ones are mostly ABEC 7. Chrome Steel Rings and retainer, PA46 retainer used in larger sizes. Si3N4 Ceramic Balls. Please refer below for Fishing Reel Ceramics.

Fishing Reel Stainless Steel Bearing Specifications

ABEC 7 Rated, Stainless Steel Rings, Balls & Retainer, Stainless Steel Metal Shields (no shields on some sizes)

Fishing Reel Ceramic Bearing Specifications

ABEC 7 Rated, Stainless Steel Rings and Retainer, Si3N4 Ceramic Balls, either PTFE Rubber Seals or Stainless Steel Metal Shields depending on size and model.


ABEC Ratings: There are some common misconceptions regarding ABEC Ratings, the higher rating does not mean the bearing will be tighter or less free spinning, it is the precision of the rings & balls. Essentially a higher ABEC rating means there is less chance of imperfections and premature failure due to manufacturing faults. This is sometimes confused with clearance ratings such as C3, C5 etc which determine the allowable play within a bearing, this is only applicable in high heat applications where heat expansion is taken into account, such as our Engine Bearings.

ABEC ratings have no way of being proven, therefore the market is flooded with Cheap bearings that claim to be ABEC 7 or 9 or 11 or 13 (eBay is full of these). The highest available is ABEC 9 and is used for extremely expensive applications, you will not be able to get a true ABEC 9 bearing easily, our manufacturer is capable of ABEC 7 and no higher.  Most bearings on the market are made to below ABEC 1 (unrated). Our lowest rated bearing is ABEC 3, this is to ensure that even our low end standard bearings are manufactured to a precise specification.

Bearing Materials.

SAE 52100 Chrome Steel

• Higher hardness for longer life ratings

• Low cost for high performance

• Good for temperatures up to 150°C

• Poor corrosion resistance (if left exposed)

This is the standard steel for most ball bearings. It is harder than stainless steel and gives greater life ratings. It also has superior low noise qualities to standard 440 grade stainless steel. Chrome steel actually has a low chromium content and is not corrosion resistant, all Chrome Steel Plaig Bearings are factory lubricated as chrome bearings require an oil/grease coating on the exterior surfaces to protect against corrosion which can contaminate the inside of the dry bearing. Chrome steel can tolerate continuous temperatures of up to 150°C. Above this temperature, bearing life is significantly reduced.

Stainless Steel

• Excellent corrosion resistance to water, salt water and many chemicals

• Good for temperatures up to 500°C

• Suitable for cryogenic applications down to -250°C

440 grade stainless steel bearings are used for greater corrosion resistance to seawater, salt spray and some acids/alkalis. They are suitable for very high temperature applications as the steel is useful in temperatures of up to 500°C. They can also be used in cryogenic applications as the steel retains its toughness down to -250°C.

Silicon Nitride CERAMIC Balls

• Very good corrosion resistance to water, salt and chemicals

• Good high temperature performance up to 1,000°C

• Electrically insulated

• Lighter than steel balls

• Very low heat expansion, less expansion and contraction between heating and cooling.

Ceramic Bearings can run faster than all steel bearings due to the lower centrifugal force generated by the ceramic balls, the speed increase for Ceramic Bearings is 30 – 40% with adequate lubrication. Ceramic Bearings are less subjected to ball skidding under initial acceleration / torque. This allows the bearing to last longer and be far more reliable. Low heat expansion allows the bearing retainers to last longer. There are no downsides to Ceramic Bearings other than they cost more to manufacture.

PTFE Heat Resistant Rubber Seals

• Excellent corrosion resistance to water, salt water and most chemicals

• Good high temperature performance.

• Maximum temperature 260°C

The PTFE Seal is rubber bonded to a metal washer. The inner lip of the seal rubs against the bearing inner ring to provide an effective seal against smaller particles such as dust and moisture while preventing lubricant leakage.

Contactless Metal Shields

Metal Shields are designed to prevent larger particles from entering the bearing and also to keep grease inside the bearing. As the shields make no contact with the inner ring, they do not increase starting or running torque.

Bearing Retainer / Cage

Retainers keep the balls evenly spaced around the raceway preventing ball to ball contact and thus allowing higher speeds. They also help to retain grease around the balls and raceways. For greater accuracy and to prevent any additional friction, it is important that the retainer is not allowed too much radial movement.

Our Chrome Steel bearings use either a Carbon Steel Crown Retainer or a PA46 Nylon Retainer. Our Fishing Reel Bearings all have Stainless Steel Crown Retainers.