Call us toll-free at: 877-552-2112 | Fax: 586-792-1105 | Tech Line is now open 8:00a.m. - 5:00p.m. Eastern Time (Monday - Friday)
Become our fan on Facebook Watch our videos on YouTube Follow us on Twitter Subscribe to our RSS feed
Trend Performance Spintron Diamond Pistons products are proudly made in USA!

Diamond Policy

Sales and Return Services


  • All prices are subject to change without notice.
  • All sales transactions conducted within the state of Michigan and North Carolina are subject to the appropriate state sales tax.

Custom Orders

  • All custom piston orders must be in writing, either faxed, mailed, or email. A custom piston order form is available for this purpose. No verbal custom orders will be accepted.
  • Orders will not be recognized and lead-time will not be effective until all necessary information, payment, and samples are received.
  • All custom piston orders with COD certified, Credit Card, or Wire Transfer terms must be paid before the order can be processed.
  • Lead time is tentative and may change without notice due to unforeseen circumstances. Every effort will be made to ship orders within the time frame quoted at time order was placed.
  • Any discrepancies with custom orders must be reported within 30 days of invoice date. A return merchandise authorization number (RMA #) will be assigned so that the order can be returned for inspection. If a discrepancy is found during inspection, the custom order will be re-made at no charge. If no discrepancy is found the product will be returned to customer at their expense or disposed of after 30 days of inspection.


  • All orders will be shipped COD certified funds or credit card (Visa, Master Card, American Express or Discover), ABSOLUTELY NO THIRD PARTY CREDIT CARDS.
  • COD Company Check terms must be applied for and approved by management


  • All orders will ship prepaid and insured, unless customer specifies to ship collect at time order is placed
  • All orders must have a shipping method specified at time order is placed. Orders without a method designated will ship Ground prepaid and insured (added to customers order)
  • Customer is responsible for inspecting shipment upon receipt and reporting any order discrepancies within 30 days of invoice date. (See Return of Merchandise for more details).

Return of Merchandise

  • A 25% re-stocking fee will be applied to all shelf items returned for credit
  • No merchandise may be returned for any reason without a RMA# (Return Merchandise Authorization Number).
  • A copy of the original invoice must accompany all returns with RMA# noted. (No third party returns)
  • Products being returned should not be altered in anyway. NO CREDIT will be issued for product that has been modified in anyway. If product has been modified it will be returned to customer at their expense or disposed of after 30 days from inspection.
  • All returns must be shipped prepaid and insured (call tags will be issued in the case of factory error). All returns should be packaged properly to prevent damage during shipping.
  • Absolutely no refunds or exchanges will be issued on special-ordered (custom PISTONS, PINS, or RINGS) or customer-altered merchandise

Warranty / Rights Reserved

  • Due to the nature of performance applications, all Diamond Racing Products are sold WITHOUT ANY EXPRESS WARRANTY OR ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  • Diamond Racing Products shall not, under any circumstances, be liable for any special revenue, cost of purchased or replacement goods, or claims of customers of the purchaser which may arise and/or result from the sale, installation or use of these parts.
  • Diamond Racing Products reserves the right to make product improvements and changes without notice and without incurring liability with respect to similar products previously manufactured.