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Fine Adjustment Screws, M4 x 0.25 Fine
2.0 mm (5/64")
These M4 x 0.25 adjuster screws, which are made from DFARS-compliant materials, 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, and all come lubricated to ensure smooth mating into compatible components..
The adjuster body is constructed of 303 stainless steel, and the ball tip is fabricated from 440 stainless steel that is fixed onto the adjuster using epoxy. These adjusters are available with a 2.0 mm (5/64") hex socket for ease of adjustment, a square head equipped with four 1.3 mm (0.05") through holes for applications where side actuation is beneficial, or a knob equipped with an access bore enabling hex adjustment.
M4 x 0.25 threaded bushings, adjuster nuts, and lock nuts, all fabricated from 510 Phosphor Bronze and vacuum-compatible down to 1 x 10-6 Torr, are also available.
For applications where the material certifications are needed, please contact Tech Support prior to purchase.
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.
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.
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.
Fast Turn-Around Times
Precision Screw Production
These adjusters are designed to be used with our M4 x 0.25 threaded bushings, available below.
These high precision M4 x 0.25 Fine Hex Adjusters feature a 2.5 mm square head equipped with four 1.4 mm (0.06") through holes. The through holes are are sized to accommodate a 1.3 mm (0.05") hex key or balldriver, thereby enabling side actuation. Please note that these adjusters are not compatible with the removable adjuster knobs sold below.
The F4MSSK1 and F4MSSK1L Removable Adjustment Knobs thread onto our M4 x 0.25 F4MSS series hex adjusters to allow adjustment without the use of a hex key. This provides quick and easy adjustments for a broad range of applications. The adjuster knobs are available in two sizes: Ø14.7 mm and Ø7.1 mm.
Our M4 x 0.25 threaded bushings are commonly used in slip fit applications where fine adjusters are needed. Due to the tolerances of our fine adjusters, we discourage press fitting these bushings. The recommended bore diameter for our M4 x 0.25 bushings is 0.2165" +0.0005/-0.0000". Please see the Integration tab for more information. For vacuum applications, we recommend a thorough ultrasonic cleaning to remove any grease or particulates prior to use.
Our N250L4P vacuum-compatible fine adjuster nut is internally M4 x 0.25 threaded and externally M6 x 0.5 threaded. These sleeves can be threaded into M6 x 0.5 tapped holes to provide M4 x 0.25 fine adjustment in a variety of applications where threaded bushings are not suitable. For vacuum applications, we recommend a thorough ultrasonic cleaning to remove any grease or particulates prior to use.
The LN4M29 lock nut features a knurled outside diameter to make gripping the nut easier when loosening or tightening. The lock nut is made from 510 Phosphor Bronze, which is vacuum rated for 10-6 Torr. Each nut features blind holes that allow a 2.0 mm (5/64") hex key to be used to help tighten the lock nut.