squadron ,
France Field, 1933 ;P-12 :Model 102,
U.S. Army Air Corps version of the F4B-1 with a 450 hp R-1340-7 engine; nine built. ;XP-12A :Model 101, 10th built P-12 with NACA cowl, a 525 hp R-1340-9 engine, and a shorter undercarriage; one built. ;P-12B :Model 102B, as P-12 with larger mainwheels and improvements tested on XP-12A; 90 built. ;P-12C :Model 222, as P-12B with ring cowl and spreader-bar undercarriage; 96 built. ;P-12D :Model 227, as P-12C with a 525 hp R-1340-17 engine; 35 built. ;P-12E :Model 234, as P-12D with semi-monocoque metal fuselage, redesigned vertical tail surfaces, some were later fitted with tailwheels instead of skids; 110 built. ;P-12F :Model 251, as P-12E with a 600 hp R-1340-19 engine; 25 built. ;XP-12G :P-12B modified with a R-1340-15 engine with side-type supercharger; one converted. ;XP-12H :P-12D modified with a GISR-1340E experimental engine; one converted. ;P-12J :P-12E modified with a 575 hp R-1340-23 engine, and special bomb sight; one conversion. ;YP-12K :P-12E and P-12J re-engined with a fuel injected SR-1340E engine; seven temporary conversions. ;XP-12L :YP-12K temporary fitted with a F-2 supercharger; one converted. ;A-5 :designation for proposed use of P-12 as a radio-controlled target drone (cancelled) ;XF4B-1 :Designation given to two prototypes for
Navy evaluation, the former Model 83 and the former Model 89. ;F4B-1 :Boeing Model 99 for the
United States Navy, split-axle landing gear and ventral bomb rack; 27 built. ;F4B-1A :One F4B-1 (BuNo A-8133) converted to unarmed executive transport for the Assistant Secretary of the Navy, fuel tank moved to upper wing centre section. ;F4B-2 :Boeing Model 223, spreader bar landing gear, frise ailerons, tailwheel replacing skid; 46 built. ;F4B-3 :Boeing Model 235, as F4B-2 but with semi-monocoque metal fuselage and equipment changes; 21 built. ;F4B-4 :Boeing Model 235, as F4B-3 but with redesigned vertical tail surfaces, 550 hp
R-1340-16 engine, underwing racks for two 116 lb bombs, last 45 built had an enlarged headrest housing a life raft; 92 built and one built from spares. ;F4B-4A :23 assorted P-12 aircraft transferred from USAAC for use as trainers. Later modified as part of Project FOX, for use as radio-controlled target aircraft. ;Model 83 :One prototype with spreader-bar landing gear and 425 hp
Pratt & Whitney R-1340-8 engine, later designated XF4B-1 for
Navy evaluation. ;Model 89 :One prototype with split-axle undercarriage and provision for a 500 lb bomb on ventral rack, later designated XF4B-1 for
Navy evaluation. ;Model 91 :As Model 83 except with metal frame wings. ;Model 100 :Civil version of the F4B-1 with upper wing tank, four built. ;Model 100A :Two-seat civil version for
Howard Hughes, later converted to a single-seater; one built. ;Model 100D :One Model 100 temporary used as a P-12 demonstrator. ;Model 100E :Export version of the P-12E for the Siamese Air Force under the designation
B.Kh.7 (), two built, one later transferred to the Japanese Navy under the designation
AXB. ;Model 100F :One civil variant of the P-12F sold to Pratt & Whitney as an engine test bed. ;Model 218 :Prototype of the P-12E/F4B-3 variant, after evaluation sold to the Chinese Air Force. ;Model 256 :Export version of the F4B-4 for
Brazilian Navy, 14 built. Locally designated
C1B. ;Model 267 :Export version for Brazil with an F4B-3 fuselage and P-12E wings; nine built. ;Model 303 :P-12E with a more powerful engine and brazier head rivets in body; a version with wing tanks was known as the
303A. ;Model 304 :As Model 303 but with the fabric covered steel tube fuselage of the P-12C; the version with wing tanks was known as the
304A. ==Operators==