NSK ball screw support bearings
NSK Ball Screw Support Bearings
NSK TAC C, TAC 03 and BSBD ball screw support bearings for machine-tool feed axes and heavy-load servo drives -- series taxonomy, size index, engineering selection and product pages for exact NSK designations.
Engineering context
Engineering reference
What NSK ball screw support bearings are
NSK ball screw support bearings are angular-contact thrust ball bearings arranged at the fixed and floating ends of precision ball screw drives. They carry axial loads from the screw, control axial rigidity for positioning accuracy, and accommodate thermal elongation of the screw shaft.
NSK groups these products into the TAC C high-rigidity series (60° contact angle), TAC 03 high-load drive series (55° contact angle), BSBD double-row BSN/BSF cartridges, and WBK ready-mounted support units. This page is the GBC authority surface for NSK ball screw support bearing discovery, size indexing and product identification.
Engineering reference
Why ball screw support bearings are used
Ball screw drives convert rotary motion to linear travel in CNC machine tools, automation axes and servo presses. Without correctly specified support bearings at both screw ends, axial loads from the nut preload and cutting forces cannot be controlled, reducing positioning accuracy and stiffness.
The fixed end typically uses a preloaded angular-contact pair for maximum axial rigidity. The floating end allows axial thermal expansion while maintaining radial guidance. Support bearing selection must be evaluated together with screw diameter, speed, nut preload and lubrication.
NSK series taxonomy
Engineering theme
TAC C — high rigidity
60° contact angle angular-contact thrust ball bearings for machine-tool feed mechanisms. Standard heavy (H) preload. Open, DDG sealed or V1V non-contact seal options.
Engineering theme
TAC 03 — high load
55° contact angle with larger balls for electric injection molding and press applications. Includes special-bore TACxx-3 upgrades within a larger envelope.
Engineering theme
BSBD - double-row
BSN (standard) and BSF (flanged) double-row cartridges with single outer ring, pre-greased and triple-lip DDU sealed.
Engineering theme
WBK - support units
Precision-machined housings with integrated TAC C bearings, locknut, seal collar and shims. DF, DFD and DFF arrangement codes.
TAC C Series — high rigidity
NSK TAC C bearings use a 60° contact angle and high ball count for exceptional axial rigidity in CNC feed drives. Catalogue sizes from the NSK Super Precision Bearings Catalogue:
| Designation | Bore | OD | Width | Angle | Role |
|---|---|---|---|---|---|
| 17TAC47C | 17 | 47 | 15 | 60° | Machine-tool feed axis |
| 20TAC47C | 20 | 47 | 15 | 60° | Machine-tool feed axis |
| 25TAC62C | 25 | 62 | 15 | 60° | Machine-tool feed axis |
| 30TAC62C | 30 | 62 | 15 | 60° | Machine-tool feed axis |
| 30TAC72C | 30 | 72 | 19 | 60° | Higher envelope TAC C size |
| 40TAC90C | 40 | 90 | 20 | 60° | Larger feed-axis support |
| 50TAC100C | 50 | 100 | 20 | 60° | Larger feed-axis support |
Universal arrangement (SU) allows duplex, triplex or quadruple combinations. Sealed variants use light-contact DDG rubber seals or V1V non-contact seals.
TAC 03 Series — high load
NSK TAC 03 bearings target heavy-duty drive systems with a 55° contact angle and larger balls for higher limiting axial load. The special-bore TACxx-3 series enables axial capacity upgrades without changing screw shaft diameter.
| Designation | Bore | OD | Width | Angle | Role |
|---|---|---|---|---|---|
| 40TAC03D | 40 | 90 | 23 | 55° | High-load drive / molding |
| TAC40-3 | 40 | 110 | 27 | 55° | Special-bore high-load upgrade |
BSBD Series — double-row BSN and BSF
BSBD double-row bearings integrate a back-to-back (DB) pair in a single outer ring for simplified mounting. BSN types include lubrication grooves; BSF flanged types include mounting bolt holes. Both are pre-greased with triple-lip DDU seals.
| Designation | Bore | OD | Width | Angle | Role |
|---|---|---|---|---|---|
| BSN3062 | 30 | 62 | 28 | 60° | Pre-greased double-row BSN |
| BSF3080 | 30 | 80 | 28 | 60° | Flanged BSF cartridge |
WBK support units
WBK ball screw support units combine NSK TAC C bearings in a precision housing with locknut, seal collar and shims. Documented sizes in the NSK catalogue:
| Unit | Bore | OD | Width | Angle | Arrangement |
|---|---|---|---|---|---|
| WBK17DF-31H | 17 | 70 | 60 | 60° | DF duplex support unit |
| WBK25DF-31H | 25 | 85 | 66 | 60° | DF duplex support unit |
Matched multi-row cartridges such as WBK25DFD-31H are retained on this family page rather than as separate product pages.
Complete size and designation index
Searchable index of NSK ball screw support designations with linked product pages and catalogue-tabulated data. Every designation below links to its engineering specification page.
| Series | Designation | Bore (mm) | OD (mm) | Width (mm) | Contact angle | Application / role | PDP |
|---|---|---|---|---|---|---|---|
| TAC C | 17TAC47C | 17 | 47 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 20TAC47C | 20 | 47 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 25TAC62C | 25 | 62 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 30TAC62C | 30 | 62 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 30TAC72C | 30 | 72 | 19 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 35TAC72C | 35 | 72 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 40TAC72C | 40 | 72 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 40TAC90C | 40 | 90 | 20 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 45TAC75C | 45 | 75 | 15 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC C | 50TAC100C | 50 | 100 | 20 | 60° | High-rigidity angular contact thrust ball bearing | View Product |
| TAC 03 | 40TAC03D | 40 | 90 | 23 | 55° | High-load drive angular contact thrust ball bearing | View Product |
| TAC 03 | TAC40-3 | 40 | 110 | 27 | 55° | Special-bore high-load angular contact thrust ball bearing | View Product |
| BSBD / BSN | BSN2052 | 20 | 52 | 28 | 60° | Double-row thrust bearing with single outer ring (BSN type) | View Product |
| BSBD / BSF | BSF2068 | 20 | 68 | 28 | 60° | Flanged double-row thrust bearing (BSF type) | View Product |
| BSBD / BSN | BSN3062 | 30 | 62 | 28 | 60° | Double-row thrust bearing with single outer ring (BSN type) | View Product |
| BSBD / BSF | BSF3080 | 30 | 80 | 28 | 60° | Flanged double-row thrust bearing (BSF type) | View Product |
TAC C vs TAC 03 comparison
| Feature | TAC C Series | TAC 03 Series |
|---|---|---|
| Contact angle | 60° (axial rigidity) | 55° (load rating) |
| Standard preload | Heavy (H) | Medium (M) or extra light (EL) |
| Ball size | Standard diameter | Larger diameter for high load |
| Primary industry | CNC machine tool feed axes | Injection molding / electric presses |
| Special configuration | Standard envelope | Special bore TACxx-3 series |
BSBD vs TAC comparison
| Topic | BSBD double-row | TAC C pairs |
|---|---|---|
| Mounting | Single outer ring; pre-greased cartridge | Duplex/triplex/quadruple combinations from universal SU bearings |
| Flexibility | Fixed DB arrangement | Configurable DG/DF/DTD/DFD arrangements |
| Sealing | Triple-lip DDU both sides | Open, DDG contact seal, or V1V non-contact seal options |
Engineering specifications overview
| Contact angle | TAC C: 60° for axial rigidity. TAC 03: 55° for load capacity. BSBD: 60° in NSK catalogue tables. |
|---|---|
| Dynamic load Ca | Published per designation in NSK catalogue tables. Multi-row arrangements scale per NSK arrangement factors. |
| Limiting speed | Grease lubrication speed limits tabulated per size. Oil-air limits require manufacturer verification where not tabulated. |
| Preload and rigidity | TAC C uses standard H preload in duplex DB/DF. TAC 03 uses M preload in NSK catalogue tables. Values are arrangement-specific. |
Preload and axial rigidity
Preload increases axial rigidity and positioning accuracy but raises friction and heat at elevated speed. NSK catalogue tables provide duplex DB/DF preload, axial rigidity and starting torque for tabulated TAC C and TAC 03 sizes.
Multi-row arrangements scale preload, rigidity and starting torque using NSK arrangement factors:
| Arrangement | Preload factor | Axial rigidity factor | Starting torque factor |
|---|---|---|---|
| Duplex DB / DF | 1.00 | 1.00 | 1.00 |
| Triplex DTD / DFD | 1.35 | 1.50 | 1.35 |
| Quadruple DTF / DFF | 2.00 | 2.00 | 2.00 |
Contact seal torque is not included in catalogue starting torque values for sealed variants.
Arrangement and configuration guidance
Engineering theme
Fixed end
Typically a preloaded duplex pair (DB or DF) at the drive end for maximum axial stiffness toward the nut.
Engineering theme
Floating end
Allows screw thermal expansion while maintaining radial guidance. Must match screw length and temperature duty.
Engineering theme
Universal SU
Single TAC C bearing supplied for custom duplex, triplex or quadruple combinations with matched preload and accuracy suffixes.
Engineering theme
BSBD DB only
Double-row cartridges use fixed back-to-back layout; cannot be reconfigured to triplex or quadruple on site.
Ordering and designation decoder
NSK ball screw support ordering codes combine bore, series, seal, arrangement, preload and accuracy suffixes. Example structure: 30 TAC 62 C DDG SU H PN7C.
- Bore / OD: Expressed in millimetres (e.g. 30 bore, 62 OD)
- Series:
C= TAC C high rigidity;03= TAC 03 high load - Seal: Open (no suffix),
DDGlight-contact seal,V1Vnon-contact seal - Arrangement:
SUuniversal single,DB/DFduplex,DUuniversal duplex - Preload:
Hheavy (TAC C standard),Mmedium (TAC 03),L/ELlighter options - Accuracy:
PN7C(TAC C),PN5D(TAC 03),P2B(BSBD)
Do not construct unsupported suffix combinations. Confirm complete ordering designations against NSK manufacturer data before quotation.
Selection guide
When selecting or requesting NSK ball screw support bearings, define:
| Selection input | Engineering relevance |
|---|---|
| NSK designation or bore/OD | Primary identification for quotation and catalogue lookup |
| Screw diameter and lead | Defines shaft bore and support envelope |
| Axial load and duty cycle | Drives TAC C vs TAC 03 vs BSBD selection |
| Fixed vs floating end | Determines duplex arrangement and preload strategy |
| Speed and lubrication | Limits grease speed rating and seal choice |
| Accuracy requirement | PN7C (TAC C) vs PN5D (TAC 03) vs P2B (BSBD) |
| Environment | Coolant, chips and seal type (open, DDG, DDU) |
Machine-tool and industrial applications
Typical NSK application contexts include:
- CNC milling machine feed drives
- High-speed NC lathe spindle and axis support
- Precision Cartesian positioning gantry axes
- Electric injection molding toggle drives
- Electric servo screw press machines
See the ball screw assemblies page for drive-level context.
NSK ball screw support product pages
Product pages for exact NSK designations.
Quotation and identification inputs
For engineering quotation, send the complete NSK designation where known, screw diameter, lead, speed, axial load, fixed/floating arrangement, seal preference and application duty. Where only bore and OD are known, include measured dimensions and any existing part marking for identification support.
Evidence and commercial boundary
Engineering values on this page and linked product pages are taken from the NSK Super Precision Bearings Catalogue unless otherwise noted. Golden Bearing Company does not imply NSK authorization, dealership or stocking unless separately confirmed. No price, stock, availability or lead-time claims are made. Numeric values for designations not tabulated in the catalogue require manufacturer verification before design sign-off.
Common questions
NSK ball screw support bearings are angular-contact thrust ball bearings at the fixed and floating ends of ball screw assemblies. They carry axial loads, control stiffness and accommodate thermal growth while maintaining screw alignment.
TAC C uses a 60° contact angle and standard heavy preload for high axial rigidity in machine-tool feed axes. TAC 03 uses a 55° contact angle and larger balls for higher limiting axial load in heavy-duty drive applications such as injection molding.
TAC C high-rigidity bearings are engineered for CNC machine tool feed mechanisms where axial rigidity and positioning accuracy are critical. Catalogue sizes include 17TAC47C through 50TAC100C.
TAC 03 high-load drive bearings target electric injection molding machines and electric press applications. The special-bore TACxx-3 series allows higher axial capacity without changing screw shaft diameter.
BSN and BSF are BSBD double-row thrust bearing types with a single outer ring. BSN includes lubrication grooves; BSF is flanged with mounting bolt holes. Both are pre-greased with triple-lip DDU seals.
Define screw bore, axial load, speed, fixed/floating arrangement and whether TAC C rigidity, TAC 03 load capacity or BSBD cartridge mounting is required. Use the size index on this page and confirm against NSK catalogue data.
Standard heavy (H) preload is the catalogue default for TAC C in duplex DB/DF arrangements. Preload, axial rigidity and starting torque values are tabulated per size in the NSK Super Precision Bearings Catalogue.
PN7C is NSK NES Class 7C for ball screw support, with axial runout matching ISO Class 2 while bore and OD tolerances align with Class 4 per NSK catalogue specification.
Special-bore bearings such as TAC40-3 use a larger housing envelope with a reduced bore, enabling higher axial load capacity without modifying the screw shaft diameter.
WBK units are precision-machined housings with integrated TAC C bearings, locknut, seal collar and shims. Arrangement codes include DF duplex, DFD triplex and DFF quadruple.
Send complete NSK designation, screw diameter, speed, axial load, arrangement, seal type and application duty. Manufacturer catalogue confirmation is required for final suffix selection.
No. Reference to NSK designations for engineering support does not imply Golden Bearing Company distributes, stocks, authorises or represents NSK unless separately confirmed.
Request an Engineering Quote
Share shaft bore, speed, torque duty and ordering designation for NSK Ball Screw Support Bearings. Send NSK designation, screw diameter, speed, axial load, fixed/floating arrangement and application duty for ball screw support bearing engineering quotation.