Mechanical properties for Condition A may not be constant from form to form. Condition A is usually the as-delivered condition from the mill or warehouse, although you can buy 17-4 stock pre-hardened to your desired spec. from some suppliers.
Condition A (solution annealed) is important, however, in that you should begin the classic 4 hour heat treat from Condition A and from no other condition. Condition A mechanical properties are not typically warranteed or assured by the supplier. If mechanical properties are requested (CMTR's) from the supplier, the material test report will typically include two heat treats eg: H900, H1100 and mechanical tests of these samples from the lot or alloy heat number, to demonstrate adequate performance.
Condition A stock is relatively easy to machine to final shape. Use speeds, feeds, and tools similar to 18-8 stock.
Use of the material, in service, in Condition A is a common misapplication for this material. Because of some confusion in the industry concerning Condition A, it is advisable to heat treat coupons along with any batches of parts and perform hardness and/or pull tests after heat treatment and final cleaning, polishing, etc.
Some users object to the discoloration or pateena formed by heat treat. Also, I have found that the heat treated surface seems more sensitive to galling. Both of these conditions can be aleviated by the electropolish process.
