Doubled Working Hub Obverse (WHO)
A Doubled Working Hub Obverse is a hub-level doubling error that occurs one step earlier in the die production chain than a standard Doubled Die Obverse. Instead of a single working die receiving a doubled impression, the working hub itself was doubled during its creation from the master die. Because every working die made from that hub inherits the doubling, WHO varieties appear on coins struck by multiple different die pairs — a key diagnostic that separates them from ordinary doubled dies.
What Is a Doubled Working Hub?
In the U.S. Mint's die production hierarchy, a master hub creates a master die, the master die creates working hubs, and working hubs create the working dies that strike coins. A Doubled Working Hub Obverse occurs when a working hub receives two slightly misaligned impressions from the master die. That working hub, now carrying doubled design elements, transfers the doubling to every working die it produces. John Wexler's doubleddie.com lists these separately from ordinary doubled dies, with WWHO numbers (WWHR for reverses).
The critical distinction is scope. A Doubled Die Obverse affects only the coins struck by one specific working die. A WHO variety affects all coins struck by every die made from the affected working hub. This means WHO varieties are distributed across multiple die pairs, and the same doubling pattern appears on coins with different reverse die characteristics.
How Does It Happen?
The working hub is created by pressing the master die into a steel blank. Before single-squeeze hubbing was fully in use (Error-Ref puts that at 1997), transferring the design took more than one impression. If the master die and the hub blank shifted between impressions, the design was imparted in two slightly different positions.
The doubling is present in the hub itself, so it carries into every working die made from it. It can still look slightly different from die to die: Wexler notes that wear to the working hub, wear to the working die, abrasion of the working die, and wear to the coins all change how it appears.
A working die made from a doubled hub can also pick up its own die-level doubling when it is hubbed, so one coin can show both. Wexler's 1962 and 1937 cent listings describe several dies like this.
How to Identify a Doubled Working Hub Obverse
WHO varieties share visual characteristics with DDOs but have distinct diagnostic features:
- Hub doubling, not shelving: The doubling is true hub doubling and is described in the same class terms as a doubled die. Wexler's descriptions are often spreads towards the centre or extra thickness, for example on the 1937, 1961-D and 1989 cent working hubs.
- Multiple dies: The key diagnostic is the same doubling on coins struck by different working dies. If two coins show the same obverse doubling but have different die markers (die scratches, gouges, polish lines) or are paired with different reverse dies, the doubling came from the hub.
- Several hubs in one year: A year can have more than one doubled working hub. Wexler lists three for the 1961-D cent obverse and four for the 1962 cent obverse.
- Magnification: Use 5x to 10x and compare with the listed photos.
Distinguishing WHO from DDO
| Feature | Doubled Working Hub (WHO) | Doubled Die (DDO) |
|---|---|---|
| Origin | Working hub creation | Working die creation |
| Dies affected | All dies from that hub | One specific die only |
| Die pair test | Same doubling across different die pairs | Unique to one die pair |
| Coins showing it | Every coin from every die made from the hub | Coins from that one die |
Distinguishing WHO from Machine Doubling
Machine doubling takes several forms, and worn dies produce a look-alike of their own; Mechanical Doubling covers the whole family.
Machine doubling (strike doubling) happens during the strike, when the die bounces or slides, and typically leaves flat shelving at the edges of design elements. Unlike hub doubling, it varies from coin to coin, because it is a striking event rather than a feature of the die or hub.
Notable Examples
1937 Lincoln Cent WWHO-001
Wexler lists a 1937 cent obverse working hub with a Class II spread towards the centre on 937 of the date and on IN GOD WE TRUST. He notes that most of the 1937 obverse doubled dies illustrated in CONECA's e-book appear to come from this hub.
1946 Roosevelt Dime WWHO-001
The 1946 dime obverse hub is listed for all three mints, 1946-P, D and S, and was reassigned from several earlier doubled-die numbers once the common hub was recognised. A doubled reverse working hub (WWHR-001) is listed for the same year.
1961-D and 1962 Lincoln Cents
Wexler lists three doubled obverse working hubs for the 1961-D cent and four for the 1962 cent (three on proofs, one on business strikes). Several 1962 listings were reassigned from earlier doubled-die numbers when those hubs were identified.
1989 Lincoln Cent WWHO-001 and -002
Two 1989 obverse working hubs show a spread towards the centre on the date and hair details, the second as extra thickness. Many dies previously listed as separate 1989 doubled dies were renumbered when the two hubs were recognised.
Collecting Tips
- Attribution: Because a doubled working hub appears on many dies, the doubling alone does not identify a die. Match the die markers as well, using Wexler's doubleddie.com listings or CONECA.
- Multiple dies tell the story: A set showing the same hub doubling on coins from different dies demonstrates the hub-level origin of the variety.
- Die state still matters: Wear and abrasion of the individual die affect how clearly the doubling shows. Early die state examples show it best.
- Check for die doubling too: A coin showing working hub doubling can also carry die-level doubling from its own working die.
- Expect renumbering: When a doubled working hub is recognised, listings that were treated as separate doubled dies are often reassigned, so older attributions on holders or flips may be out of date.