Linear Components Technical Introduction

Nook Industries manufactures a full range of linear slide systems and slide systems components. The PowerTrax™ line of linear components includes solid shell LBB linear bearings, self-aligning EXCEL™ linear bearings, HG Hardened and Ground Shafting, Pillow Blocks and complete slide systems.

Linear Bearing Types

Excel™ Linear Bearings

Designed to fit into precision bores, these bearings are self aligning and offer long life. Precision hardened and ground bearing plates with conforming ball tracks are contained in a molded thermoplastic housing.


These bearings are used in lower load applications where self alignment is not required. The precision fit between the bearing and shaft is built into the bearing as a result of the solid steel shell. These bearings utilize a molded plastic ball retainer assembled inside a hardened and ground shell.

ILBB Instrument Series

Similar in construction to LBB linear bearings, Instrument Series Linear Bearings are small diameter, high precision bearings with stainless steel shells. When matched with Instrument Series Linear Shafting, ILBB Linear Bearings provide high performance with .0001 to .0003 inch clearances.

ILBB Linear Bearings are used in light load, high precision applications where low friction guidance is required such as medical and semiconductor equipment.

Open Series Bearings

For applications requiring fully supported shafts, "open" bearings are available in both LBB and EXCEL™ types. In an open bearing, one ball circuit is removed to allow the mounted bearing to translate along a supported shaft.


LBB and EXCEL™ bearings are available in sealed and unsealed versions. ILBB bearings are unsealed.


Nook PowerTrax™ linear bearings use a combination of high performance thermoplastic, chrome-steel bearing balls, and either a one piece hardened steel shell or precision ground hardened steel bearing plates. (See Image 1 in Figure 1 Below)

EXCEL SELF-ALIGNING Plastic Resin NYLON-66 Hardened Chrome Steel Hardened Steel N/A N/A Nitrile
LBB SERIES Hardened Steel Black Oxide Hardened Chrome Steel N/A Acetal Resin Steel Black Oxide NItrile
STAINLESS STEEL SERIES Stainless Steel Hardened Chrome Steel N/A Acetal Resin Stainless Steel N/A
INSTRUMENT SERIES 440C 440C N/A Acetal Resin Stainless Steel N/A

Excel™ Maximum speed

When used in high speed or high impact environments, EXCEL™ bearing capacities should be de-rated as shown in the chart. Divide the rated load by the load factor to determine the appropriate bearing size. (See Image 2 in Figure 1 Below)

Linear Shafting


Nook PowerTrax™ HG Shafting, made from high quality alloy steel, is manufactured and stocked for immediate shipment in our Cleveland, Ohio facility, in diameters from 5 to 80mm and ¼ to 4 inches. Stainless Steel shafting is available from ¼ thru 2 inch diameter.

Standard diameters can be cut to your specified length and shipped within 24 hours of receipt of your order. Contact Nook Industries, Inc. for availability of special diameters.

Case Hardness

PowerTrax™ HG alloy shafting is induction hardened to Rc 60-63. Stainless steel shafting is hardened to Rc 50-55. Instrument Series Shafting is hardened to Rc 55-60. The case depth on all PowerTrax™ HG Shafting is precisely controlled for optimal performance. The extremely hard surface minimizes wear and is resistant to nicks and scratches. (See Image 3 in Figure 1 Below)

Surface Finish

PowerTrax™ HG shafting is centerless ground to a consistently smooth surface finish of 14 microinches rms or less. Excellent surface finish and hardness maximize the efficiency and life of linear bearings.


PowerTrax™ HG shafts are straight within 0.002 of an inch per foot cumulative when shipped from the factory. Handling or machining of shafting can cause the material to bend.

Predrilled & Tapped Holes

PowerTrax™ HG alloy shafting is stocked with radial holes drilled and tapped to accept a continuous shaft support rail. Continuous support prevents shaft deflection when used to support heavy loads or for long travel lengths. Radial holes can be supplied in stainless steel shafts from ½" to 2" diameter.

Precision End Machining

PowerTrax™ HG shafting can be supplied pre-machined to application requirements. Send a detailed sketch or blueprint for a prompt quotation. See page 212 for descriptions of machining offered by Nook Industries. Templates for machining are available on our website.

Length Tolerance

PowerTrax™ HG shafting cut to your specified length will have a standard length tolerance of +1/32" up to 2" and ±1/16 above. Closer tolerances are available for an additional charge. Non-precision chamfered ends are standard on all cut shafting.

Shaft Supports

Aluminum support components for end mounting or continuously supporting PowerTrax™ HG shafting are available for inch sizes ½" to 2". (See Image 4 in Figure 1 Below)

Self-Aligning Pillow Blocks

PowerTrax™ Pillow Blocks simplify mounting of PowerTrax™ Linear Bearings. They are available with EXCEL™ Bearings to fit shafts from ¼ to 2 inch and 10 to 50mm. PowerTrax™ Pillow Blocks provide the precision bearing bores necessary for linear bearing installation.

Mounting Tolerances

The PowerTrax™ Pillow Block mounting surface to centerline dimension is held to ±0.001 inch. Bearings will self-align up to ±½°.


All PowerTrax™ Pillow Blocks are manufactured from precision machined, thick walled, extruded aluminum.

Pillow Block Seals

PowerTrax™ Pillow Blocks are supplied complete with lip seals. The sealed pillow block keeps lubricant in and dirt and debris out resulting in smoother operation and longer bearing life.

Linear Slide Systems

Series 100 Slide Systems

PowerTrax™ Series 100 slide systems are pre-assembled and ready to mount. Series 100 slides consist of combinations of PowerTrax™ Linear Ball Bearing Pillow Blocks, HG shafting, carriage plates and shaft supports. Aluminum carriage plates include threaded steel inserts at key mounting locations.

Series 200 Slide Systems

PowerTrax™ Series 200 slide systems are assembled slides which include:

  • Linear bearing pillow blocks
  • Integrated end supports
  • HG linear shafts
  • Carriage Plate
  • PowerTrac™ Ball Screw assembly

Many options are available for these slide systems. Different screw styles and leads, protective boots, special motor mounts and custom carriage plate machining is available. Contact Nook Industries, Inc. for assistance.

MM Slide™ Mini Slide Systems

PowerTrax™ MM Slides™ are metric-dimensioned compact slide units. They utilize lightweight aluminum components and include an integrated carriage/pillow block assembly for a reduced overall height. A wide variety of screw diameters, leads and nut styles are available. These systems include:

  • EXCEL™ linear bearings
  • Integrated end supports
  • HG linear shafts
  • Carriage/pillow block assembly
  • 1 Lead screw assembly
Figure 1