[b]ASTM A193/A193M-06a, "Standard Specification for Alloy-Steel and Stainless Steel Bolting Materials for High Temperature or High Pressure Service and Other Special Purpose Applications."
http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/A193A193M.htm?L+mystore+uans4890
Table 1 gives composition, Tables 2 & 3 give Mechanical properties in inch-pound and metric, respectively.

Mech props depend on size. For diameters < 2.5 inch, B16 has YS 105 ksi, TS 125 ksi, elongation 18%, max hardness 321 HB or 35 HRC.

[b]ASTM A194/A194M-06, "Standard Specification for Carbon and Alloy Steel Nuts for Bolts for High Pressure or High Temperature Service, or Both."
http://www.astm.org/cgi-bin/SoftCart.exe/DATABASE.CART/REDLINE_PAGES/A194A194M.htm?L+mystore+uans4890
The mech. data for nuts is given as 'Proof Load' on either a threaded mandrel or a hardened steel cone for various thread sizes. E.g., for 1-inch Grade 4 hex nut on threaded mandrel, proof load is 90,900 pounds_f and proof stress is 175 ksi.  For heavy hex: 106,000 pounds_f and proof stress is 150 ksi for heavy hex.  Proof loads are most definitely not design loads.


These 2 standards cost $48 & $40.  If you might need others, buy the 2006 Annual Book of ASTM Standards vol. 01.01, either book or CD, for $216.  http://www.astm.org/cgi-bin/SoftCart.exe/BOOKSTORE/BOS/TOCS_2006/01.01.html?L+mystore+sxhl5033+1154373416

Lacking a copy of the standard, consider contacting the fastener supplier and asking them about the specification properties for their bolts and nuts made to ASTM A193.  However, be prepared for a response that they comply with ASTM A193 specifications.

Thanks a lot for the reply, JLSeagul and Kenvlach.