Hey there! Thank you for your query on the Jones Stephens T60060 torque wrench. Generally, torque wrenches like this one should be calibrated at least once a year or every 5,000 cycles in order to meet the ISO 6789 regulations. Regarding your second query, we, unfortunately, do not have any information about whether this torque wrench has a calibration certificate. For further technical assistance, it would be best to contact Jones Stephens and submit a ticket through their website. We hope this information helps! Thank you for visiting PlumbersStock! Have a nice day!