Hex Adjusters, M3 x 0.25 Fine

Features

• Hex Adjusters Feature a 1.5 mm Hex Socket
• Removable Adjustment Knobs Available for Hex Adjusters
• Adjuster Screws with Integrated Adjustment Knob
• Threaded Bushings, Nuts, and Lock Nuts for Threading Integration

These M3 x 0.25 adjuster screws are ideal for limited space applications that require fine (250 μm/rev) resolution. Each threaded component is individually tested with a master gauge set that ensures the interchangeability of our fine adjustment components. The adjuster body is constructed of 303 stainless steel and the ball tip is constructed using 440 stainless steel that is fixed onto the adjuster using epoxy. The hex adjusters feature a 1.5 mm hex socket, which provides a simple way to make fine adjustments. The fine adjuster screws come lubricated to ensure smooth mating into compatible components.

Integrating Fine Adjustment Screws Into Optomechanical Systems

The assembly process begins by producing the appropriately sized mating hole for the threaded bushing. Given the close fit between the threaded bushing and the mating adjuster screw, we caution against using a press fit to assemble these products. For our own production needs, we use a permanent anaerobic adhesive that provides excellent long-term performance.

We recommend using Loctite Anaerobic Adhesive product number 680 or equivalent. In order to ensure maximum strength between the bonded parts, we strongly urge the user to follow carefully the instructions provided by Loctite, which specify the amount of clearance between the threaded bushing and the mounting plate. The most common source of failure is not allowing for the proper clearance between the parts being bonded since this clearance provides for the proper volume of adhesive.

When assembling, apply a small amount of the Loctite adhesive to the threaded bushing only. Rotate the bushing as it is installed to ensure a uniform distribution of the adhesive. After insertion, remove any excess adhesive from around the part.

As shown in the figure to the right, the flange on the mating bushing is designed to support the axial load of the screw and bushing assembly.

Drilling and Tapping

While we recommend using our fine adjusters with the appropriately matched threaded bushing (sold below), it is also possible to incorporate them directly into a part or material by creating a threaded hole. For the adjusters on this page, the diameter of the pilot bore should be 2.766 mm ± 0.037 mm. The corresponding metric drill bit size is 2.75 mm (0.1083") and the corresponding imperial drill bit is size 7/64" (0.1093"). The hole can then be tapped with TAPM3025. For fine pitch threads, it is especially important to tightly tolerance the pilot bore because of the shallow thread depth. For more information, see our taps and drill bit kit page.

OEM & Custom Precision Screws

Thorlabs manufactures custom and high volume OEM precision screws and bushings with various diameters, lengths, and threads. To inquire about custom or OEM precision screws, please contact Technical Support or use the "Contact Us" form to the right. A specialist will contact you within 24 hours or the next business day.

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Precision Screw Capabilities

Thorlabs' in-house machine shop, located in Newton, NJ, gives us the ability to quickly produce large quantities of precision screws and bushings. We are equipped to manufacture screw diameters ranging from 2 mm to 20 mm with lengths up to 165 mm and a maximum thread pitch of 200 TPI. Our standard adjuster screw design has a hardened steel ball tip to provide a single point of contact; for other applications we are able to provide adjusters without the steel ball. Custom orders can be achieved on a case-by-case basis. For large orders of an item, Thorlabs passes on to the customer the cost savings associated with planned production of high volumes of that item. For more information on Thorlabs' discount pricing policy, click the "V" link to the right. We also offer a large variety of stock precision screws, which are available here.

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Fast Turn-Around Times
Our experienced, highly skilled machinists are running our on-site Citizen Swiss Screw Machines 24 hours a day, allowing us to produce high-volume custom and OEM orders. Each machine is capable of running unattended, producing one screw every 30 to 120 seconds. This flexibility allows us to fulfill multiple orders at once without sacrificing quality.

High Quality
Thorlabs inspects all of our fabricated precision screws and bushings after the initial fabrication process and right before packaging. All inspections adhere to the ANSI AQL1.5 acceptable quality level, which states that if a certain percentage, based upon the amount of product in a certain lot, does not meet specification, then the entire lot is not sold. This ensures that all customers receive the highest quality product every time and that all items will be of equal performance.

Precision Screw Production