Comparing Inconel 625 vs 718 starts with the part specification. A buyer needs to know which grade the drawing requires, what condition the material must arrive in, and which acceptance tests apply. A similar-looking round bar is not evidence that two alloys are interchangeable.
Identify the grade before comparing quotations
Alloy 625 is identified as UNS N06625 and W.Nr. 2.4856. Alloy 718 is UNS N07718 and W.Nr. 2.4668. Put the required identifier on the inquiry and purchase order so a quotation cannot rely on an abbreviated trade name alone.
The essential technical difference
Alloy 625 obtains its strength primarily through solid-solution strengthening and is widely considered for corrosion-resistant components. Alloy 718 is age-hardenable, making its heat-treatment condition especially important when purchasing bars for strength-critical parts. These distinctions are described in the Special Metals technical bulletins linked below.
The practical purchasing implication is to compare the specified delivery conditions, rather than comparing generic tensile values copied from different datasheets. The engineer-approved specification must govern the order.
Questions to answer before ordering bars
- Does the drawing call for 625 or 718, and does it include a UNS identifier?
- What product specification and revision apply to the bar?
- What delivery condition is required, and who performs any subsequent heat treatment?
- What diameter, length, straightness and machining allowance are needed?
- Which mechanical tests and additional inspections are acceptance requirements?
- How must each bar remain traceable after cutting?
Why two offers for the same grade can differ
A quotation may cover a different surface finish, delivery condition, cut length or inspection scope. A lower unit price can also exclude documents or testing included by another supplier. Request a line-by-line compliance statement and have any exception stated before placing the order.
For a machined component, send the drawing or describe the finished dimensions and the planned production sequence. This lets the supplier review the requested raw material size without assuming that the finished component dimensions are the ordered bar dimensions.
Can Alloy 718 replace Alloy 625?
Do not authorize a substitution from grade names alone. Ask the responsible engineer to assess the actual environment, loading, product specification and processing route. A supplier quotation confirms a proposed supply scope; it does not replace component design approval.
Related products and next steps
Review our Alloy 625 bar and Alloy 718 bar pages.
Shanghai Phoenix Alloy Co., Ltd. handles international inquiries with its Jiangsu manufacturing base. Send your grade, dimensions, quantity and specification for a review of the proposed supply requirements.
Technical references
Special Metals: Alloy 625 technical bulletin; Special Metals: Alloy 718 technical bulletin. INCONEL is a trademark of the Special Metals group; alloy designations here identify material grades.