New, Slide Rule Express Service! Order a rule today and it'll ship tomorrow. No more waiting for checks to arrive and then to clear. Just tell me that "the check is in the mail", and I'll just take your word for it! This is possible because of the extremely low observed correlation between an appreciation for slide rules and a tendency to stiff people. Yes! this is all due to slide rule lovers' credit worthiness as a class (see Editorial Section). Exciting, isn't it? My usual mode it USPS Priority Mail ($4 for 3 day delivery), but I will ship overnight (USPS Express Mail), if you want to pay for it. (please add $22 to order, instead of $4.) (Sorry, Slide Rule Express is available to U.S. residents only because I don't know how much to tell international customers to send for shipping. So email me and we'll work it out.)

  • There is no extra charge for using Slide Rule Express!
  • Note: email orders must be received by 7PM Mountain Standard Time for guaranteed next-day shipping.
  • All rules are returnable, no questions asked, within 10 days of your receipt (rules must be in original condition).

    My mailing address is:

    David Crate
    725 E. Mtn. Sage Dr.
    Phoenix, AZ 85048

    NOTE! Slide Rule Express is OPTIONAL. If you prefer to contact me prior to placing an order, please feel free to do so. I am happy to answer any questions that you have regarding my slide rules or about rules in general. (Other subjects may be treated as well but will elicit unpredictable responses woefully lacking in Political Rectitude.) The impetus behind this "express" system is to get slide rules in the hands of the "slide rule needy" as quickly as reasonably possible. If you find it unuseful, ignore it and just send me an email with whatever is on your mind. Maybe you can explain the number "e" to me. (Yeah, I know it's the base of natural logarithms. But I'm looking for something a little more intuitive.)

    - Rule prices reflect scarcity as well as features.
    - Rule lengths quoted refer to scale length, overall length is typically 1-2 longer that scale length. Please send email to me requesting further detail on any rule in which you have an interest..
    - Prices DO NOT include shipping.
    - International orders will have a $5 handling charge in addition to actual shipping cost.
    - Prices are subject to change. Please do not ask for yesterday's price today.
    - Rules may be returned, in original condition, within ten calendar days of customer receipt. Price of rule will be refunded after it is returned and determined to be in original condition. I try to be very fair in this - giving my customers the benefit of the doubt. If the rule has not been damaged, it can be returned! Please notify me that you are returning a rule.

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  • The 3 components of a Slide Rule ExpressOrder:

    Please send me email(, telling me:

    1. Which rule(s) you want.
    (N.B. the minimum order for a slide rule express is $25, excluding shipping.)

    2. Your (domestic U.S.) shipping address.

    3. That your payment is on its' way to the address just below.
    (remember to include $4 for Priority Mail shipping, or $22 for Overnite delivery)

    And ... what happens:

  • I will ship you rule the next business day! (Be sure to let me know in your email if this a Slide Rule Express order so I won't take my usual sweet time about it. AND be sure to let me know if you're paying $22 for overnight delivery! Otherwise I'll just ship it 3-day Priority.)