Frequently Asked Questions
- How do I mount/secure a bushing?
- What are the recommended hole sizes for press-fits and slip-fits?
- What type of lubrication is used between the threads of matched sets?
- Can I alter or customize any of your standard items?
- Do you provide material certificates?
- What is the maximum allowable applied force on a screw?
How do I mount/secure a bushing?
A bushing can be mounted either using a press-fit or slip-fit. For a press-fit, the hole should be .0002"-.0003" smaller than the barrel diameter of the bushing. A slip fit requires a hole .0005"-.002" larger than the barrel diameter of the bushing (and adhesive to secure the bushing in place).
What are the recommended hole sizes for press-fits and slip-fits?
Below are the recommended hole sizes for our bushings (and matched set bushings):
TB187 & TSB187 series
Press-fit hole diameter: .2502"-.2503"
Slip-fit hole diameter: .2510"-.2525"
TB250 & TSB250 series
Press-fit hole diameter: .3122"-.3123"
Slip-fit hole diameter: .3130"-.3145"
TB3 & TBM3 series
Press-fit hole diameter: .1764"-.1765"
Slip-fit hole diameter: .1772"-.1787"
TB2 series
Press-fit hole diameter: .1553"-1554"
Slip-fit hole diameter: .1561"-.1576"
What type of lubrication is used between the threads of matched sets?
We use Apiezon M Silcone-Free High-Vacuum grease for lubrication. This is applied standard to all matched sets. If you do not want lubrication applied to your matched sets, please write "no grease" on the comments section when checking out.
Can I alter or customize any of your standard items?
Yes, we are a full service machine shop, and make everything in our New Jersey facility. You can send us a RFQ with any requests, or you can attach a drawing of your own and send it to info@kozakmicro.com. Once we receive your information, we will review it and send a quote as soon as we can.
Do you provide material certificates?
Yes, we will send you a copy of the applicable material certificate(s) if requested.
What is the maximum allowable applied force on a screw?
The list below shows the axial loads at which our screws (and matched sets) failed, along with the recommended maximum loads. The maximum applied axial load is calculated by measuring the force at which failure occurs when the screw is moving/rotating, and then adding in a safety factor. Failure is characterized by the screw (and bushing) seizing due to galling.
Please keep in mind that these load ratings are under ideal conditions. The actual maximum load may be less than stated if there are non-axial forces and vibrations present. If the screw is rotated frequently and/or is rotated at a high RPM, that too can negatively affect the maximum load. Additionally, as the applied load increases, so does wear and the chances of galling, so it is a good idea to keep applied loads lower to prevent this. A good rule of thumb is to use half of the load at failure as a working maximum. This will ensure that the screws function properly and don’t fail prematurely.
TS3 & TSBM3 Series:
0.25mm pitch: Load at failure: 65 lbf (289 N) dynamic (while screw is rotating)
Recommended working max load: 32.5 lbf (144.5N)
0.20mm pitch: Load at failure: 52 lbf (231 N) dynamic (while screw is rotating)
Recommended working max load: 26 lbf (115.5N)
0.10mm pitch: Load at failure: 32 lbf (142 N) dynamic (screw is rotating)
Recommended working max load: 16 lbf (71N)
0.05mm pitch: Load at failure: 22 lbf (98 N) dynamic (screw is rotating)
Recommended working max load: 11 lbf (49N)
TS187 & TSB187 Series:
100 TPI: Load at failure: 110 lbf (489 N) dynamic (screw is rotating)
Recommended working max load: 55 lbf (244.5N)
127 TPI: Load at failure: 86 lbf (386 N) dynamic (screw is rotating)
Recommended working max load: 43 lbf (193N)
200 TPI: Load at failure: 55 lbf (248 N) dynamic (screw is rotating)
Recommended working max load: 27.5 lbf (124N)
254 TPI: Load at failure: 44 lbf (195 N) dynamic (screw is rotating)
Recommended working max load: 22 lbf (97.5N)
TS250 & TSB250 Series:
80 TPI: Load at failure: 130 lbf (584 N) dynamic (screw is rotating)
Recommended working max load: 65 lbf (292N)
100 TPI: Load at failure: 111 lbf (495 N) dynamic (screw is rotating)
Recommended working max load: 55.5 lbf (247.5N)
127 TPI: Load at failure: 87 lbf (390 N) dynamic (screw is rotating)
Recommended working max load: 43.5 lbf (195N)
200 TPI: Load at failure: 56 lbf (250 N) dynamic (screw is rotating)
Recommended working max load: 28 lbf (146N)
254 TPI: Load at failure: 45 lbf (200 N) dynamic (screw is rotating)
Recommended working max load: 22.5 lbf (100N)
508 TPI: Load at failure: 23 lbf (102 N) dynamic (screw is rotating)
Recommended working max load: 11.5 lbf (51N)