Professional torque calculation for maintenance engineers.
Three-pass assembly, K-factor lookup, stress check, hot retorque —
in one tool. Runs offline in your browser.
One-time payment. No subscription. Activate on up to 3 devices.
Not a generic calculator. Every feature maps to a real maintenance problem.
Automatic 30 / 70 / 100% sequence with cross-pattern order. Output prints as an on-site assembly card.
7 lubricant types (MoS₂, copper paste, nickel, PTFE, dry…) with range min/mid/max — based on published test data.
Proof-load ratio with GREEN / AMBER / RED gates. Blocks calculations that would over-stress the bolt.
Triggers mandatory warning when design temperature exceeds 200 °C — something cheap calculators miss.
Catches Class 150 specs at 4 MPa before you get to the field. ASME B16.5 and HG/T 20592 supported.
After activation, everything works in-browser. No data leaves your device. Good for restricted plant networks.
Every output references the relevant standard. Auditable by your mechanical integrity team.
No subscriptions, no seat counts, no surprises.
Secure checkout by LemonSqueezy · Visa, Mastercard, PayPal, Apple Pay
A lifetime license key for the BoltTorque web calculator at bolttorqcalc.com. You can activate the key on up to 3 devices (any combination of desktop browsers and mobile). After activation, the calculator works offline.
No. One payment of $29 gives you lifetime access to the current major version (v1.x) including all updates. If there's ever a v2.0 with major new capabilities, it may be a separate purchase, but v1.x updates are free forever.
The individual license covers up to 3 devices for one user. For plant-wide or team deployment with centralised license management and invoicing, email us to arrange a team license. 工厂团队授权请邮件联系以获取专用报价和对公发票。
Yes. We offer a 14-day no-questions refund. Just reply to your purchase receipt email.
No. It's a calculation and assembly-card tool, not an engineering judgment tool. Turn-of-nut procedures, bolt tensioning, and non-standard joints still need a qualified engineer. The tool flags these cases and defers.
You can use the generated assembly cards as on-site work aids, with your own site-specific approval. The underlying calculations cite ASME PCC-1-2019, EN 13555, and GB/T 16823.3 directly — those standards (not this tool) are the authoritative references.
暂不提供中国增值税发票。LemonSqueezy 自动发送的购买收据（含金额、日期、公司名）适用于个人报销和企业财务记录。如工厂采购必须取得增值税发票，请等待我们上线国内独立站（开发中）。
We do not issue Chinese VAT invoices at this stage. The automatic LemonSqueezy receipt is suitable for personal reimbursement and corporate expense records. A mainland-China site with VAT invoicing is in development.