A little history...
C.S. Osborne & Co. has been making upholstery tools since 1826. They started offering covered button parts, machines, and dies after purchasing Wade Button Company in the early 1990s. Osborne is now the only manufacturer of 1920-style machines and dies, but happily is going strong and doing great. Wade's "1920" competitor, Defiance Button Machine Co., was sold off in pieces in the 1980s. Some of their tooling was bought by Puzant "Tony" Buzantian, who founded AB Precision Co. and manufactured button machines and dies for C & C Metal Products under their "Dyna Line" brand until his death 2015. C & C now re-sells Osborne machines and dies under the C & C name.
Handy Button Co. (now Handy Kenlin Group) is Osborne's only domestic competition. Their respective machines are somewhat compatible: button dies are interchangeable***, but other dies are not unless machines are retrofitted. Handy's direct competitor was once Maxant Button & Supply Co., which manufactured machines and dies compatible with Handy Jr. No. 1 and 20. Maxant's machine button division was sold to Burgess Manufacturing in the 1980s, then again to a Burgess employee in 2002, then...? —their hand cover division was sold recently to their biggest customer and is now Maxant Buttons, LLC.
Handy emerged from bankruptcy in 2011 a much leaner company. Their focus is now upholstery; button dies smaller than #22 (as well as non-button dies) are no longer in production, and they dropped their once extensive apparel and specialty button lines.
Osborne saw this an opportunity to introduce their own line of smaller dies and buttons. They hired a consultant to determine sizing for #16, #18, and #20 based on Wade's old #22 tooling. HOWEVER... Wade's #22 sizing is smaller than international standard; upholsterers who years ago purchased Wade #22 dies also bought Wade's non-standard #22 buttons, never realizing that sizing was brand-specific because everything worked fine.
This leads to Osborne's sizing discrepancy:
Osborne #16, #18, #20, and #22 dies are manufactured to Osborne's own standards, which are slightly smaller than international standard. Early on, we chose to modify the inside diameters of these sizes to match standards that have been in place since cover button machines were introduced in the 1840s. You may request an unmodified die but be aware your choice of compatible backs will be limited to a handful of "small diameter" Osborne Wire Eyes and Flat Backs.
We stock Osborne manual machines and dies exclusively because they are the most versatile in the world —made in USA for over 150 years and built to last forever. We are proud of our long partnership with Osborne and look forward to many more years together! ...despite the weird size thing.
***All Handy button dies (both old and new styles) fit Osborne machines. Osborne button dies manufactured after April 2010 fit Handy machines. Shank ("stem") diameters of older Osborne (and Wade) button dies are too wide to fit Handy machine bases without modification.