NMT Ltd.
Corporate Communications Department
NMT 7007 CD/P4ATBTB Triplex Super Precision Angular Contact Ball Bearing Set – Japan NMT High-Rigidity Heavy-Cutting Spindle Solution
Product Overview
The NMT 7007 CD/P4ATBTB is a pre-assembled triplex super-precision angular contact ball bearing set, comprising 3 rows of single bearings arranged in a specific matched configuration (<>>). With a total width of 42 mm (14 mm per row × 3 rows), a 35 mm bore, and a 62 mm outer diameter, this set features a 15° contact angle (CD type) design, delivering exceptional axial and tilting rigidity while maintaining ultra-high speed potential.
This bearing set offers a basic dynamic load rating of 33.8 kN and a static load rating of 28.5 kN – more than double the capacity of a single 7007 series bearing (14.8 kN / 9 kN) – making it ideal for heavy-cutting, high-feed-rate machining applications. The P4A super-precision tolerance class ensures micron-level spindle rotational accuracy.
Model Code Decoding – Understanding NMT 7007 CD/P4ATBTB
Code Meaning
7007 Basic series designation, 35 mm bore
CD 15° contact angle design (versus 25° for AC) – optimized for ultra-high speeds with lower heat generation
P4A Super-precision tolerance class – dimensional accuracy P4, running accuracy exceeding P4
TBTB Triplex pre-assembled set designation – 3 bearings matched in a specific arrangement (typically Tandem-Back-to-Back-Tandem), with end faces ground and light preload preset at factory. Not interchangeable with individual bearings
Light Preload Preload level set to light, balancing temperature rise at high speeds with system rigidity – ideal for comprehensive high-speed heavy-cutting conditions
Critical Note: This is not a universal matchable set (GB/GC). It is a fixed matched bearing set. All 3 rows are precision-fitted at the factory. End users do not need to adjust preload – simply install out of the box.
Core Performance Advantages
1. Triplex Configuration – Ultimate Rigidity and Load Capacity
With 3 rows of rolling elements sharing loads, radial and axial system rigidity increases by over 200% compared to single-row bearings. The 33.8 kN dynamic and 28.5 kN static ratings confidently handle severe impact loads from heavy milling and powerful turning operations.
2. 15° Contact Angle – Perfect Balance of Speed and Rigidity
Compared to 25° contact angle, the 15° contact angle generates less frictional heat at equivalent speeds, enabling higher limiting speeds. The triplex arrangement compensates for the reduced axial load capacity of the 15° angle, achieving both high speed and heavy load capability simultaneously.
3. Factory-Preset Light Preload – Time-Saving and Error-Free
The bearing set undergoes matched face grinding and light preload setting at the NMT factory. Users can install directly without complex preload calculations or shim selection, significantly reducing assembly time and eliminating human error.
4. P4A Super-Precision Grade – Micron-Level Spindle Accuracy
The P4A tolerance class guarantees minimal radial runout and axial play, meeting stringent surface finish and dimensional tolerance requirements of high-precision machining centers and grinders.
5. Integral Ring Design
One-piece inner and outer rings enhance overall set rigidity and minimize cumulative assembly errors between components.
Typical Applications
The NMT 7007 CD/P4ATBTB is specifically engineered for demanding heavy-duty precision equipment:
Heavy-Duty Vertical/Horizontal Machining Centers – powerful milling and boring spindles
High-Rigidity Turning Centers – heavy-depth, high-feed turning spindles
Precision Grinding Machines – heavy-load grinding wheel spindles
Large CNC Drilling Machines – high-axial-force drilling and tapping spindles
Gear Cutting Machines – hobbing and shaping spindles
Technical Installation Notes
⚠️ This is a non-universal matchable set. The 3 bearings are supplied as a complete matched set. Do not interchange or mix with other bearings of the same model.
⚠️ Follow NMT's supplied assembly drawings and recommended shaft/housing fit tolerances strictly.
⚠️ Maximum limiting speed depends on lubrication method, cooling conditions, and mounting fit. Please consult NMT technical engineers for customized speed recommendations.
NMT Quality Commitment
Japan NMT (Enmutī) applies stringent end-face matching grinding and preload control to every triplex bearing set, ensuring highly uniform load distribution across all rows. Each 7007 CD/P4ATBTB set undergoes full-parameter inspection before shipment, delivering P4A accuracy and light-preload rigidity for long-term reliable rotational support in your heavy-cutting spindles.
Choose NMT 7007 CD/P4ATBTB for:
✅ Japanese precision assembly craftsmanship
✅ Triplex extreme system rigidity
✅ 15° angle balancing high speed and heavy load
✅ Factory-preset light preload – ready to install
✅ P4A super-precision running accuracy
✅ All-weather reliability under heavy-cutting conditions