A fiber grade and a tow designation describe different things. T300 or T700S identifies a particular manufacturer’s fiber grade; a label such as 3K describes a filament count in a tow. Neither label is a complete specification for the finished laminate.
Check the full material name
Toray lists named carbon fiber grades and their available tow forms separately. Retain the manufacturer, complete grade designation and relevant product information when a material is proposed. Do not remove a suffix because another listing uses a shorter marketing name.
Follow the material into the part
The reinforcement may then become a fabric, tape or other intermediate product before it enters a laminate. Ask which product is actually being purchased and how it is used with the resin. A grade name on its own leaves the fabric construction and part layup unresolved.
Compare the supplied construction
If two quotes both say T700, ask for their precise material descriptions before comparing them. Equally, two fabrics carrying the same tow count need not contain the same fiber grade. Keep the sample’s material definition with its inspection or test evidence. Manufacturer fiber data remains fiber data; it should not be relabelled as a measured property of an unidentified finished component.
Further reading: Toray CMA: carbon fiber grades and tow forms.