RHP7005CTDULP4Super-Precision Angular Contact Ball Bearings, 25 x 47 x 12 mm, 15 Degree Contact Angle, ABEC 7 / P4, Phenolic Cage, Universally Ground Duplex, Light Preload – 2 Pcs Forming One Pair

Product Description

What this part is

RHP 7005 C.T.DUL.P4 super-precision angular contact ball bearings, 25 mm bore x 47 mm outside diameter x 12 mm wide, with a 15° contact angle. They are built to ABEC 7 / ISO P4 accuracy with phenolic cages, and their faces are universally ground so they stack to a defined light preload. This is spindle-grade hardware, not general-purpose bearings.

Quantity and configuration

The −1/2PR suffix means half of a pair — one bearing per half-pair designation. This listing ships 2 Pcs, so you get both halves: two universally ground singles that together make one complete pair. Set them back-to-back (DB), face-to-face (DF) or in tandem (DT) as your spindle drawing requires, and the ground offsets deliver the specified light preload automatically, with no shims or spacers to grind. Each piece can also be used on its own, or matched with any other bearing of the same designation.

Decoding the designation

7005 — single-row angular contact ball bearing, ISO 70 series, 25 mm bore. 25 x 47 x 12 mm. The 70 series is the light-section family, so a 7005 is slimmer and faster than a 7205 on the same 25 mm shaft.
C — 15° contact angle in RHP nomenclature. RHP’s other common angle code is E for 25°.
T — phenolic (laminated fabric) cage. Light, self-lubricating and quiet at speed, which is why it is the standard super-precision spindle cage.
DU — duplex universally ground. The ring faces are ground so any two pieces of the same designation stack to a known preload in any orientation.
L — light preload. RHP’s scale runs L light, M medium, H heavy.
P4 — ISO tolerance class 4, equivalent to ABEC 7. RHP also writes this class EP7.
−1/2PR — half a pair, so one bearing per that designation. Two are supplied here.

DU and SU are mutually exclusive: DU means universally ground for duplex mounting, SU means universally ground as a single. These are the DU form.

What these specs mean in practice

The 15° contact angle is the defining spec and it is a deliberate trade. A shallow angle puts the ball load path closer to radial, so the bearing runs faster and cooler and handles radial load well, but it carries less thrust and gives less axial stiffness than a 25° or 30° bearing. That is the right choice for a high-speed spindle where the cutting thrust is modest. Fit a 15° bearing where a 25° was specified and the spindle loses axial rigidity and can deflect under thrust; fit a 25° where 15° was specified and it runs hotter at the same speed. The angle is not interchangeable, and it is the single most common way a super-precision replacement goes wrong.

Preload is the second trade. Preload removes internal clearance, so the spindle gains stiffness and the balls are prevented from skidding at high speed — that is what holds a cutting tool on size. It also generates friction heat continuously, cutting or idling. Light preload is the high-speed choice: less heat, less stiffness. Never mix preload classes in one stack, and never mix contact angles.

Universal grinding is what makes a pair like this straightforward to fit. On a non-universally-ground bearing you have to order a factory-matched set and keep the pieces together for life. Here the offsets are ground to a standard, so these two mate correctly with each other and with any other same-designation piece — and a stray half on a shelf can be reunited into another working pair.

P4 / ABEC 7 is about running accuracy, not load. It tightens bore, outside diameter, width and runout tolerances so the spindle turns true. That accuracy is worth nothing if the housing and shaft seats are not ground to matching tolerance, so check the machine before fitting P4 bearings to a worn spindle.

Published specifications

Bore d: 25 mm
Outside diameter D: 47 mm
Width B: 12 mm (per bearing); 24 mm total width for the two pieces stacked
Contact angle: 15°
Bearing type: single-row angular contact ball, ISO 70 series
Precision class: ISO P4 / ABEC 7 (RHP EP7)
Cage: phenolic (laminated fabric)
Grinding: universally ground for duplex mounting (DU)
Preload: light (L)
Closure: open
Sale unit: 2 Pcs — two −1/2PR halves forming one complete pair

Installation and setup notes

Handle super-precision bearings clean and cool: unwrap only at the machine, keep the preservative oil on until fitting unless you are flushing to a specified lubricant, and never spin a dry bearing with compressed air. Mount with a press against the ring being fitted, never through the balls. Before stacking, confirm both pieces carry the same designation, the same contact angle and the same preload letter, then set the orientation the spindle drawing calls for — back-to-back for moment stiffness, face-to-face for a self-aligning tendency, tandem for one-direction thrust. Both housing and shaft seats need to be ground to a tolerance that matches the bearing, or the P4 accuracy is wasted.

Interchange guidance

RHP’s bearing business became part of NSK, so the current-brand equivalent is an NSK 7005 super-precision at 15°. 2MM9105WI-CR-DUL is carried as the Fafnir and Timken designation for the same configuration: the 2MM prefix is Fafnir’s 15° code, CR is a phenolic outer-land-riding cage and DUL is duplex universally ground light preload. Other same-angle equivalents: FAG B7005-C-T-P4S-UL, NSK 7005 CTYDULP4, SKF 7005 CD/P4A, NTN 7005 C GD2GLP4. Beware the near-misses: Fafnir 3MM9105WI is 25°, NSK 7005 A5 is 25° and 7005 A is 30°, and SKF 7005 ACD is 25°. Those are dimensionally identical — same 25 x 47 x 12 mm envelope — but they are related sizes with a different contact angle, not equivalents. Note too that a 7205 is the same 25 mm bore in the heavier 72 series at 25 x 52 x 15 mm, so it is neither a drop-in nor a related size. Always carry across the contact angle, the grinding code and the preload letter as well as the size.