Contact Us

Looking for a Product? Have any questions? Reach out to Us. We will get back to you within a day!

4280 Marie Court
Fremont, CA, 94536
United States


At USA Pen Company, we craft pens and pencils in a small utility workshop of a house in Elk River, Minnesota.  We use exotic wood and acrylic to hand make our pens. Our selection over the past few months has evolved into an assortment of contemporary designs... Come take a look at our collection and choose your favorite to either gift to your loved one, or keep all for yourself! 

All our pens and pencils are handmade in the United States of America (USA).

Welcome to the art of pen and pencil making at USA Pen Company. 

Would you rather have synthetic plastic or the feel of rich natural wood in your hand? We make our pens with carefully selected exotic wood from different parts of the world! 

Do visit our Gallery and Lookbook. If you like any pen currently not available in our "BUY NOW!" page, email us the details and we will specially handcraft and ship it to you within 14 days of your order. 

We look forward to serving your needs. Thanks!

Centrifuge Guide

Service AI support guide for centrifuge questions. Please feel free to email us at

What is the minimum/maximum fill volume for my tubes?

Service AI

Fixed angle rotors: all open-top, thinwall tubes, requiring multi-piece metallic caps, are to be filled as far as possible and sealed. For thickwall tubes and bottle assemblies, the minimum fill volume is half of its maximum fill volume.

Swinging bucket rotors: all thinwall tubes should be filled to 2 - 3mm from the top. 

All OptiSeal TM and Quick-Seal TM tubes are to be filled per instructions in the Rotors and Tubes manuals (LR-IM-, TLR-IM-, and JR-IM-). 

It will be important to note that there are exceptions to these guidelines. More detailed information and fill volumes for each tube and bottle type used in a given rotor is found in each rotor operator's manual and in the Beckman Coulter Rotors and Tubes manuals , which are available from Beckman Coulter.

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