Oh, the 2.5mm (roughly 0.1") makes a difference. The spec I quoted was for 1" or greater...
Nope, that is for less than 1". It should be good if it is 4140. It seems that for smaller diameters, AISI-4130 is more commonly used, which is significantly weaker.
Some comments:
AISI 4130 is a chromium-molybdenum steel that is in general use due to its well-established heat-treating practices and processes techniques. It is available in all sizes of sheet, plate and tubing. Bar stock of this material is also used for small forgings under one-hal finch in thickness. AISI-4135 is a slightly higher carbon version of AISI 4130, is available in sheet, plate and tubing.
AISI 4140 is a chromium-molybdenum steel that can be heat treated in thicker sections and to higher strength levels than AISI 4130. This steel is generally used for structural machined and forged parts one-half inch and over in thickness. It can be welded but it is more difficult to weld than the lower carbon grade AISI 4130.
OK, so agreed Fred, without a little more material information, it's hard to tell. Let me get the other source. OK, 1" round bar has
Annealed - F_ty = 62ksi
Normalized - F_ty = 93 ksi
You're probably looking at a bearing strength, so for bar, forgings
Annealed - no data
Normalized - 158 ksi
Normalized and heat treated (with Ftu = 140) - 225 ksi
Normalized and heat treated (with Ftu = 160) - 252 ksi
Normalized and heat treated (with Ftu = 180) - 284 ksi
edit: Ian, my first source is a MIL spec manual called the MMPDS (Metallic Materials Properties Development and Standardization). It's a slightly more current version of something that was called...(something else can't remember). We just 'have' it, although I do know for fact that it is available from off of a website hosted by a Big10 school that makes a name for itself with engineering.
I also use the ASMD (Aerospace Materials Database), which we have both in several extremely large old books, and as an online website we need to log into.