Grade 7 Titanium CNC Machining Services — Ti-0.2Pd (UNS R52400)

Engineering Challenge

The corrosion benefit of Grade 7 is entirely dependent on the 0.12–0.25% Pd addition. A bar that drifts below the lower limit behaves like Grade 2 in the reducing-acid environment, with no corrosion advantage. The MTR must show Pd content measured by ICP-OES or XRF, and the mill must be on the buyer qualified-supplier list.

Our Machining Approach

We confirm the MTR Pd value against the customer specification at incoming inspection. We also flag any mill not on the buyer qualified-supplier list, since the chemistry controls across the industry are not uniform. Customer-supplied material is accepted only with a complete MTR; partial or absent chemistry data is treated as a deviation.

Engineering Outcome

Verified Pd content at the agreed acceptance range, with full chemistry traceability to the original heat.

Engineering Challenge

Grade 7 corrosion performance in HCl, H2SO4, H3PO4, and similar reducing media is highly sensitive to surface condition. Iron contamination, embedded abrasive, or a damaged passive film can seed localized attack. In some reducing-acid services, even small surface defects grow rapidly.

Our Machining Approach

We segregate Grade 7 work from carbon-steel / 316L work where the order scope requires it, use dedicated tooling and workholding, and schedule ASTM B600 alkaline cleaning + acid pickling per the agreed inspection plan. Passivation schedules are matched to the customer downstream service environment.

Engineering Outcome

Surface free of iron and abrasive embedment, with the passive film intact at the point of shipment. Corrosion qualification remains the customer responsibility.

Engineering Challenge

Despite the Pd addition, Grade 7 fabrication behavior is essentially identical to Grade 2: gummy-chip machining, iron-contamination sensitivity, weldability under standard procedures.

Our Machining Approach

We machine, form, and weld Grade 7 to the same procedures as Grade 2, with the additional step of Pd content verification at incoming inspection. Cutting parameters, weld-prep geometry, and surface-preparation schedule are matched to the Grade 2 baseline, not to alloyed grades.

Engineering Outcome

Cost-effective fabrication consistent with CP-Ti workflow, while preserving the corrosion benefit. Final tolerance and surface-finish commitment is confirmed after CAD, drawing, material condition, and inspection method review.