7021 Angular Contact Bearing: Dimensions & P4 Variant Guide
The 7021 angular contact bearing features a 105 mm bore, 160 mm outside diameter, and 26 mm width, engineered specifically for high-speed machinery requiring precise radial and single-direction axial load management. Standard 7000 Series angular contact bearings accommodate combined loads in industrial equipment across Indonesia, ranging from machine tool spindles in Cikarang factories to heavy fluid pumps in Surabaya.
However, matching physical dimensions alone is not enough to guarantee smooth operation. Ordering a bearing based solely on the base part number 7021 can lead to catastrophic spindle failure if crucial precision, contact angle, and sealing suffixes are overlooked.
What are the exact dimensions and specs of the 7021 angular contact bearing?
The base 7021 angular contact bearing is defined by its 105 mm inner diameter (bore), 160 mm outer diameter, and 26 mm boundary width[1]. Within the 7000 Series, these physical dimensions form the standard envelope for medium-to-large high-speed rotating shafts. Under the premium HI-TEC SILVER tier, the specialized 7021C/P4 2RZ variant delivers high-precision rotational performance combined with integrated protection.
The 7021C/P4 2RZ variant incorporates specific engineering features designed for demanding operating environments. The suffix 'C' denotes a 15-degree contact angle optimized for high rotational speeds, while 'P4' indicates ISO Class 4 super-precision manufacturing tolerances. The '2RZ' designation specifies dual non-contact synthetic rubber seals that provide low friction while excluding dust and moisture[2][3].
| Specification Field | Base 7021 Specification | HI-TEC SILVER 7021C/P4 2RZ Variant |
|---|---|---|
| Bore Diameter (d) | 105 mm | 105 mm |
| Outside Diameter (D) | 160 mm | 160 mm |
| Width (B) | 26 mm | 26 mm |
| Precision Rating | Standard ISO | ISO Class 4 (P4 Precision) |
| Contact Angle | Standard 7000 Series | 15-Degree (C Suffix) |
| Sealing Type | Open | 2x Low-Friction Non-Contact Seals (2RZ) |
| Brand Tier | HI-TEC | HI-TEC SILVER |
For industrial maintenance teams verifying inventory, reviewing the exact 7021 bearing product page ensures that both envelope dimensions and internal technical specifications match the intended equipment installation.
Why are 7021 series bearings not interchangeable by size alone?
Bearings sharing the same 7021 base number are not universally interchangeable, because size alone does not dictate precision tolerances, contact angles, or sealing specifications. Installing a standard open 7021 bearing into a CNC spindle designed for a 7021C/P4 2RZ precision unit creates immediate operational issues, including excessive runout, rapid thermal expansion, and premature failure.
Selecting the correct 7021 variant requires evaluating critical application criteria beyond envelope dimensions:
- Precision Class (P4 vs Standard): A P4 precision bearing maintains strict running accuracy and tight dimensional tolerances, essential for high-speed spindles. Standard precision bearings allow greater shaft runout, leading to tool chatter in milling operations.
- Contact Angle (C Suffix): A 15-degree contact angle ('C') optimizes the bearing for ultra-high rotational speeds with lower axial load capacity, whereas larger angles increase axial stiffness at the expense of maximum speed capability[1].
- Sealing Configuration (2RZ): Non-contact 2RZ seals protect internal raceways from workshop dust without introducing the heavy drag or heat generation associated with full-contact rubber seals[2][3].
- Load Direction & Pairing: Single-row angular contact bearings support axial loads in one direction only[1]. Incorrect orientation or improper preloading during installation will destroy the raceway.
Before ordering replacement units for machinery in Jakarta, Bandung, or Semarang, maintenance personnel should cross-reference full suffix markings. Exploring the broader angular contact ball bearings category helps clarify how contact angles and internal clearances alter operational performance. Indonesian buyers can confirm exact part numbers directly with HI-TEC experts via WhatsApp (+62 823-1004-6527) for rapid verification.
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Frequently Asked Questions
What are the exact dimensions of a 7021 angular contact bearing?
A 7021 angular contact bearing has a bore diameter of 105 mm, an outside diameter of 160 mm, and a width of 26 mm. These dimensions apply across standard and precision variants within the 7000 Series.
What does the 7021C/P4 2RZ bearing specification indicate?
The 7021C/P4 2RZ specification identifies a 105x160x26 mm bearing with a 15-degree contact angle (C), ISO Class 4 super-precision tolerances (P4), and dual low-friction non-contact rubber seals (2RZ) under the premium HI-TEC SILVER line.
Are all 7021 series bearings interchangeable based on size alone?
No, 7021 bearings are not interchangeable by size alone. Variants differ significantly in precision tolerance (such as P4 class), contact angle (e.g., 15-degree 'C'), and seal design, which directly affect maximum speed, axial load capacity, and running accuracy.
How do I order HI-TEC SILVER 7021 precision bearings in Indonesia?
You can order HI-TEC SILVER 7021 precision bearings by reaching out directly to HI-TEC ASIA via WhatsApp (+62 823-1004-6527) or emailing info@hitecbearings.id to verify exact variant availability and secure fast nationwide shipping across Indonesia.
References
- SKF. https://www.skf.com/products/super-precision-bearings/angular-contact-ball-bearings/productid-7021%20ACDGA%2FP4A (2026-10-16)
- 61908-2RZ Deep groove ball bearing with seals or shields. https://www.skf.com/us/products/rolling-bearings/ball-bearings/deep-groove-ball-bearings/productid-61908-2RZ (2026-10-26)
- 61824-2RZ Deep groove ball bearing with seals or shields - SKF. https://www.skf.com/us/products/rolling-bearings/ball-bearings/deep-groove-ball-bearings/productid-61824-2RZ (2026-10-25)