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Mechanical Components

Mechanical components are precision hardware that convert rotary motion into controlled linear motion in CNC machine tools, industrial automation systems, and motion control applications, including ball screws, profiled rail linear guides, and supporting accessories that complete a linear axis assembly. PLC Direct stocks Bosch Rexroth mechanical components across ball screw, linear guide, and linear motion accessory product families, sourced through independent suppliers and available as surplus sealed, refurbished, and used hardware.

Where Are Mechanical Components Used in Industrial Environments?

Mechanical components are used wherever a machine axis requires precise, repeatable linear positioning; from the X, Y, and Z axes of a CNC machining center to the gantry systems of automated assembly equipment and the feed mechanisms of packaging and converting machinery. They are replacement items in any facility where ball screw wear, linear guide carriage damage, or motion axis failure requires an exact-specification replacement to restore positioning accuracy.

Facilities and operations that depend on mechanical components include:

CNC machining centers and turning centers where Rexroth ball screws drive spindle, saddle, and cross-slide axes, and where screw wear or nut backlash develops over high-cycle service and reduces positioning accuracy below acceptable tolerances.

Semiconductor and electronics manufacturing equipment requiring sub-micron positioning repeatability from profiled rail linear guides on pick-and-place, wire bonding, and wafer handling gantry stages.

Packaging and converting machinery using ball screw-driven linear axes for format change positioning, where worn screws introduce position drift that causes product registration errors at high line speeds.

Gantry robots and Cartesian motion systems in automotive and general manufacturing assembly cells, where profiled rail carriages on horizontal and vertical axes require replacement after extended duty cycles produce measurable play or increased friction.

Injection molding and press equipment where ball screw assemblies drive mold clamping or ejector plate linear motion, and where nut wear or screw deflection affects clamp force consistency and cycle repeatability.

A worn or failed mechanical component on a motion axis directly degrades positioning accuracy or disables the axis entirely, making exact screw diameter, lead, accuracy class, and carriage size matching essential before ordering a replacement.

Which Brands of Mechanical Components Does PLC Direct Stock?

The current inventory in this collection comprises Bosch Rexroth hardware across four confirmed product families.

Rexroth Ball Screw Series (R055): Precision ground and rolled ball screw assemblies for CNC and automation linear axes, where the part number encodes the screw diameter, lead, accuracy class, and nut type required to replicate the original axis specification.

Rexroth Linear Guide Rail and Carriage Series (R030, R038, R065): Profiled rail linear guide systems including rails, carriages, and runner blocks for high-load, high-accuracy linear motion in machine tool and automation applications.

Rexroth Linear Motion Accessories (R480): Support units, end bearings, and mounting hardware for ball screw and linear guide assemblies, required when replacing a complete axis assembly rather than a screw or carriage alone.

Rexroth Pneumatic and Linear Motion Components (R431, R432, R433): Pneumatic valve blocks, flow control fittings, and actuator accessories supporting Rexroth linear motion and pneumatic positioning systems in machine and automation applications.

PLC Direct stocks Bosch Rexroth mechanical components as surplus sealed, refurbished, and used hardware, depending on available inventory.

What Should You Know Before Ordering Mechanical Components?

Hardware condition options: Surplus sealed units are unused and in original manufacturer packaging. Refurbished units have been inspected and restored to functional operating condition. Used units are tested and operational, with conditions stated on each product listing. For precision components such as ball screws and linear guides, used units may have accumulated wear that affects positioning accuracy even when the unit functions correctly.

Compatibility and part identification: Ball screws and linear guides must be matched by diameter, lead, accuracy class, and mounting interface. A screw with a different lead will produce incorrect axis travel per motor revolution and will not replicate the original axis behavior, even if it fits mechanically. For linear guide carriages, the rail size, carriage length, and preload class must also match the installed rail to achieve the correct load rating and stiffness. The full Rexroth part number, including all suffix characters, is the only reliable way to confirm a compatible replacement.

Warranty: All mechanical component hardware purchased from PLC Direct carries a standard 1-year warranty covering defects and functionality, applicable to surplus sealed, refurbished, and used products.

PLC Direct supplies mechanical components for replacement and maintenance and does not provide system design, programming, or integration services.

Frequently Asked Questions

A ball screw converts rotary motor torque into linear thrust, driving the axis carriage along its travel path. A linear guide constrains and supports the moving carriage, maintaining alignment and carrying the load perpendicular to the direction of travel. Most precision linear axes use both: the ball screw provides drive force and positioning, while the linear guide provides structural support and guidance.

The ball screw lead, the linear travel per one full screw revolution, is embedded in the Rexroth part number and must match the original exactly. Installing a screw with a different lead changes the axis travel-per-revolution ratio, which means the machine's motion controller will calculate incorrect positions unless the drive parameters are also changed, an adjustment that falls outside PLC Direct's scope of supply.

The preload class determines the internal clearance, or precompression, between the rolling elements and the raceways, directly affecting axis stiffness and backlash. A lower preload class introduces more compliance and backlash than the original specification, which can degrade positioning accuracy in high-precision applications. The preload designation is part of the full Rexroth part number and should be confirmed from the original component or machine documentation before ordering.

Used and refurbished ball screws may have accumulated wear that reduces positioning accuracy or increases backlash compared to a new or surplus sealed unit, even when they remain mechanically functional. For applications where axis positioning accuracy is critical, confirming the acceptable backlash and repeatability tolerances against the used unit's actual condition before installation is advisable.

The rail width, carriage length, and mounting hole pattern must all be confirmed, as Rexroth produces multiple carriage sizes for each rail profile, and carriages from different size classes are not interchangeable on the same rail. The carriage height and flange configuration also vary within a rail size series, so measuring the installed carriage dimensions or recording the full part number from the carriage label before ordering is strongly recommended.