Linear Shafts and Bearings from Automotion
A linear shaft is a straight, precision machined bar on which linear bearings run to create a linear guide system to support or guide the movement of equipment in a linear fashion. Available in hardened steel, hardened stainless, 303 and 316 stainless, and aluminium. We can also manufacture on short lead times linear shafts to your drawing with custom machining, keyways, circlips grooves, drilled and tapped holes and more.
As specialists in linear motion systems we offer you a choice of materials and sizes. We also machine shafts to your specific requirements. So whether you need lightweight aluminium rails for use in aviation applications, stainless steel components for when exposure to water or corrosive chemicals is a factor or just require a ball bushing to suite your linear shaft, our knowledgable technical engineers are always on hand to provide assistance.
Make sure you download a free Linear Motion Handbook here and utilise our free CAD to help you save time planning your projects.
Linear Shaft Bars
Automotion Components large range of linear shafting includes hardened steel shaft bars, corrosion resistant shaft bars and hollow shaft bars. We can also modify these standard shafts (drilling, tapping etc.) to suit customer requirements.
Made from the hardest type of stainless steel (AISI 440C) with a ground and polished surface. Ideal for use in applications in which there may be some corrosive materials and which also demand high wear resistance. Diameters from 6 - 60mm.
Softer than hardened linear shaft rods. To be used with ceramic or other bearings not containing hardened ball bearings. Diameters from 6-60mm.
Marine grade AISI 316 stainless steel shafts. Extremely corrosion resistant, but relatively soft and cannot be used with hard linear ball bushings. To be used with ceramic or other bearings not containing hardened ball bearings. Diameters from 6-60mm.
Generally used with linear bearings. Load capacity depends on the length of the shaft and how it is supported. Diameters from 5 - 60mm.
Very hard rods and can be used with standard linear bearings. The hollow nature offers an element of weight reduction. Diameters from 12 - 50mm.
Lightweight aluminium linear shafts with hard aluminium oxide ceramic coating to increase durability. Often used with self-lubricating ceramic linear bushes. Diameters from 8 - 50mm.
Linear Bearings
There are many styles of linear bushings to complement the linear shaft rods, making it very easy to mount your moving piece of equipment to them. Thanks to the recirculating balls inside the bushings, linear shaft rods and bearings offer a lower friction, more energy efficient solution than linear guides. For loads that may rotate, why not have a look at our splined shaft rods and nuts?
Standard, closed, open, compact and adjustable linear bushings. Simply press fit for shafts from 5 - 60mm in diameter. Available in steel, and nickel plated or stainless steel on request. Available in steel, and nickel plated or stainless steel on request.
For shafts from 6 to 60mm in diameter. With circular or square flange, and double complement centre flange versions are available for higher load applications.
With a floating plate mechanism, these superball linear bearings offer self-aligning clearing adjustments. they allow high loads to be put on smaller diameter shafts and often also results in a much longer bearing system lifeline. For use with hardened shafts only.
Standard, flanged and pre-mounted to aluminium carriages. With either resin ball or stainless steel ball retainers. Available in closed, open, long version, adjustable and square or circular flange.
Designed to run in 'dirty' environments. They can alo run on soft shafting, such as aluminium and stainless steel linear rods. They are compatible with corrosion resistant linear shaft rods. Available in standard and self-lubricating version of closed, open and thin wall ceramic bearings.
How do Linear Bearings work?
Linear Shaft Supports
Automotion Components offer a range of shaft support rails up to 6 metres long and for shaft diameters from 12mm to 40mm. The full length linear shaft rod support reduces the amount of bend in the shaft rod, thereby increasing rigidity and accuracy of linear motion.
Closed bearings pre-mounted into aluminium housings. Available in aluminium alloy or stainless steel, for shafts with 8 - 50mm in diameter. Especially suited for fully supported linear shafts on rail.
Hardened steel shafting or corrosion resistant linear shaft rods mounted on aluminium alloy support rails, for use with open flanged or unflanged carriages. To suit shaft diameters from 16 to 50 mm. Length up to 6 metres.
Aluminium shaft clamps to be used with shaft support rails L1780. Pneumatic shaft clamps also available .
Steel splined linear shafts and spline nuts from Automotion Components. These are excellent for loads that might exert torsional forces on the bearing. The ridges and grooves stop the ball bearings from rotating along the shaft, so that in practice, a splined linear shaft and nut system can replace the need for two linear rod rails.
Associated Products
Our popular linear rail systems with either flanged or unflanged carriages, widths 15, 20, 25, 30, 35, 45 and 55mm, and lengths up to 4 metres. Rear-fixing rails or ultra-low profile carriages also available.
Only for horizontal linear translation applications. An affordable easy sliding rail system for heavy duty shorter stroke applications (lengths up to 2 metres).
Linear Shaft Materials
Hardened steel linear shafting (L1770 – L1771)
Carbon steel to BS 070M55 hardened to 60-65 HRC. Carbon Steel B.S. 070M55 is a medium carbon steel which is used when greater strength and hardness is desired than in it’s as rolled condition. Extreme size accuracy, straightness and concentricity are combined to minimise wear in high speed applications. Suitable for use with all types of linear bushings.
Corrosion resistant steel (L1772)
440C is a high carbon chromium martensitic stainless steel, generally supplied in the annealed condition with a maximum hardness of 50-55 HRC. Characterised by good corrosion resistance in mild domestic and industrial environments, including fresh water, organic materials, mild acids, various petroleum products, coupled with extreme high strength, hardness and wear resistance when in the hardened and tempered condition. Used for parts requiring a combination of excellent wear resistance, plus reasonable corrosion resistance. Typical applications are: ball bearings and races, bushings, cutlery, chisels, knife blades, pump parts, surgical instruments, valve seats etc. Material magnetic in all conditions. Suitable for use with all types of linear bushings.
Stainless steel AISI 303 (L1773)
303 is a free machining chromium-nickel austenitic stainless steel with good strength and good corrosion resistance, as supplied in the annealed condition. Characterised by excellent machinability and non galling properties due to its higher sulphur content, which has the effect of slightly lowering its corrosion resistance. It is however, fairly resistant to general atmospheric corrosion, general foodstuff s, sterilizing solutions, dyestuffs, most organic chemicals, plus some inorganic chemicals. But has very limited resistance to acids. 303 cannot be hardened by thermal treatment, but strength and hardness can be increased substantially by cold working, with subsequent reduction in ductility. It is used primarily for production runs involving extensive machining, or complex parts requiring excellent machinability. Typical uses are: architectural components, food processing equipment, dairy equipment, dying industry, hardware and kitchenware manufacturing and allied industries. Commonly used to manufacture bolts and nuts, bushes, gears, shafts, valve bodies and fittings etc. Material is non magnetic in the annealed condition, but can become mildly magnetic following heavy cold working. Annealing is required to rectify if necessary.
Not suitable for use with linear ball bushings, please use ceramic bearings.
Stainless steel AISI 316 (L1774)
316 is a chromium-nickel-molybdenum austenitic stainless steel with good strength and excellent corrosion resistance, as supplied in the annealed condition. Characterised by high corrosion resistance in marine and industrial atmospheres, it exhibits excellent resistance to chloride attack and against complex sulphur compounds employed in the pulp and paper processing industries. The addition of 2% to 3% of molybdenum increases its resistance to pitting corrosion and improves its creep resistance at elevated temperatures. Also it displays good oxidation resistance at elevated temperatures and has excellent weldability. AISI 316 cannot be hardened by thermal treatment, but strength and hardness can be increased substantially by cold working, with subsequent reduction in ductility. It is used extensively by the marine, chemical, petrochemical, pulp and paper, textile, transport, manufacturing and allied industries. Typical uses are: architectural components, textile equipment, pulp and paper processing equipment, marine equipment and fittings, photographic equipment and x-ray equipment etc. Material non magnetic in the annealed condition, but can become mildly magnetic following heavy cold working. Annealing is required to rectify if necessary.
Note: Optimum corrosion resistance is achieved in the annealed condition. Not suitable for use with linear ball bushings; please use ceramic bearings.
Linear Shafts General Guidance
As well as standard cut to length shafting, Automotion Components can offer many specials including imperial shafts, different tolerances and non-standard diameters.
We can also machine shafts to your requirements so if you have a specific requirement, please contact our Sales team. Below are examples of just some of the machining we can do to shafting on a quick turnaround.
Linear Ball Bushings Technical Information
Applications
- Computers and peripheral equipment.
- Recording equipment.
- Linear motion systems.
- Multi-axis drilling machine.
- Printing machines.
- Food packaging machines.
- Punching presses.
- Tool grinders.
- Assembly systems.
- Card selectors.
Features
Interchangeability
Our linear bushing systems are designed to have full interchangeability, with other manufacturers’ parts. For shafting see part numbers L1770 to L1785.
High precision retainer
The single body retainer guides 4-6 ball circuits. It precisely guides the balls with a smooth motion.
Tolerance of housing bore
Normal fit is standard, pressed fit is for without clearance.
| Part no. | Normal fit | Pressed fit |
| L1706 to L1733 | H7 | K6, J6 |
| L1706...-1 to L1733...-1 | H7 | J7 |
Rigid outer sleeve
The hardened and precisely ground outer sleeve is made of bearing steel.
L1750 bushing carriages
Consists of light aluminium case and L1706 type linear bushing, so the installation can be finished simply by bolting. Longer life can be obtained by adjusting the orientation of the ball circuits in the linear carriage element against the direction of load.
Tolerance of shaft
| Part no. | Normal fit | Tight fit |
| L1706 to L1733 | h6 | k6 |
| L1706...-1 to L1733...-1 | f6, g6 | h6 |
Load Rating
Basic dynamic load rating C
The basic dynamic load rating is defined as the constant load both in direction and magnitude under which a group of identical linear bushings are individually operated. 90% of the units can travel 50Km without failing due to rolling contact fatigue.
Basic static load rating C0
If a linear bushing is subject to an excessive load or impact, a permanent deformation occurs between the raceway and the rolling element. The basic static load rating is defined as the static load that gives a prescribed constant contact stress at the centre of the contact area between the rolling element and raceway receiving the maximum load.
Superball Linear Ball Bushings
- 3 x the load rating and 27 x the travel life of conventional linear bushings
- Self-aligning feature
Features
Higher load ratings
The uniquely designed ball plate (in the outside diameter of the bushing), is made of hardened steel. The precision ground groove is slightly larger than the ball size, which provides greater contact area between the balls and the ball plate, and as a result, provides 3 x higher load ratings of conventional linear bushings.
Self-alignment
The ball plate has a convex shape to provide a pivot point at the centre which allows self-alignment up to ±0.5°. This self-alignment capability eliminates any possibility of edge pressure caused by inaccurate machining, errors on mounting, or shaft deflection.
Tolerance of shaft and housing bore
| Part no. | Shaft Ø d1 | Tol. h6 μ | Housing bore Ø d2 | Tol. H7 μ |
| L1740.010 | 10 | +0 to - 9 | 19 | +21 to -0 |
| L1740.012 | 12 | +0 to - 11 | 22 | +21 to -0 |
| L1740.016 | 16 | +0 to - 11 | 26 | +21 to -0 |
| L1740.020 | 20 | +0 to - 13 | 32 | +25 to -0 |
| L1740.025 | 25 | +0 to - 13 | 40 | +25 to -0 |
| L1740.030 | 30 | +0 to - 13 | 47 | +25 to -0 |
| L1740.040 | 40 | +0 to - 16 | 62 | +30 to -0 |
| L1740.050 | 50 | +0 to - 16 | 75 | +30 to -0 |
FAQs
Linear Shafts vs Rotary Shafts: What's the difference?
A linear shaft is required when a sliding motion is needed, especially when that motion needs to be fine-tuned and guided. However, if you need to transmit power over a distance, or if you need to change the relative speed of some rotation, a rotary shaft will act as the better solution. Please get in touch with one of our expert technical engineers if you need more advice.
What are Linear Shafts used for?
Linear shafts are a critical component in linear motion machines and applications. Uses can often be found in the aerospace, medical, packaging and industrial sectors, amongst others. Our linear shafts can be manufacture with different diameters, strengths and materials and offer superior support and bearing for different machines and mechanisms.
What are the types of Linear Shafts?
Linear shafts typically come in three types: Solid, hollow, or supported. Solid shafts are available in a range of materials such as steel, stainless steel grades and aluminium. These can be manufactured with male or female threaded ends to aid installion. Hollow shafts are typically used for weight saving or when cables need to be threaded through the centre. Fully support shafts, or shaft support rails, are used when deflection due to loads involved are a concern.
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