Brace and bit

How it works

The user presses on the rounded head with one hand or the chest and turns the offset handle with the other, so the crank swings the bit around its axis. Griffith’s 1908 school textbook describes the brace as the tool that holds the various kinds of bits used in boring, and Noyes’s 1910 manual adds that it also holds screwdriver bits, dowel-pointers and similar tools. The chuck takes the square tang of the bit between its jaws: the user opens the jaws by turning the sleeve, inserts the tang, then reverses the turn to grip the shank.

A ratchet brace adds a pawl mechanism, which lets the handle act in one direction or the other only. Both Griffith and Noyes say this allows boring where the crank cannot make a full revolution, near a wall or a corner. The size of a brace is its sweep, which Noyes defines as the diameter of the circle through which the swinging handle turns.

Anatomy

Head: The knob at the top on which the user presses; the 2004 U.S. military manual lists it as part (1) of the brace.
Crank (sweep): The offset arm. Its swing diameter gives the brace its size.
Crank handle: The revolving grip that the user turns.
Ratchet mechanism: Pawls and a ratchet wheel that let the chuck turn one way while the handle swings back and forth.
Chuck: Jaws and a screw sleeve that grip the shank of the bit; Millers Falls’s 1878 catalog distinguishes the steel sweep from the steel jaws of its Barber braces.
Bit: The replaceable cutter with a square tang; the auger bit is used for all ordinary boring in wood according to Griffith.

Variants

Plain brace: Chuck, handle and knob without a ratchet; Noyes calls this sufficient for ordinary use.
Ratchet brace: Adds pawls for boring in confined spaces; Spofford’s 1881 patent added a rod with a spring pawl so that the bit could not slip backward at the moment of starting.
Household bit brace: A light brace with open ratchet and alligator jaws; Stanley’s 1929 catalog lists an 8-inch-sweep example.
Universal angular bit stock: An angled attachment sold by Millers Falls in 1878 so that the brace could bore in corners and between beams.

Specifications

Sweep · in: Sizes in the 1878 Millers Falls list run from 8 to 12 inches (Barber ratchet braces at 8, 10 and 12 inches); Stanley’s 1929 household brace is 8 inches.
Bit size range for fixed bits · in: The 2004 U.S. military manual states its drilling procedure for a bit of fixed size from 1/4 inch up to a 1 inch maximum; Griffith says auger bits come in sets of thirteen from 1/4 to 1 inch by sixteenths.

Safety and care

Safety

Griffith warns that a drill bit in a brace is easily broken, that the brace must be held firmly, and that the direction of boring must not be changed by tilting the brace after the bit has started into the wood.

Care

Keep auger bits from striking nails or other metal, and lay them down with care because they dull easily (Griffith, 1908).
Apply a light coat of oil to metal surfaces; clean dirt and shavings from gear teeth; hang manual drills on a rack or store them in a safe, dry place (TO 32-1-101, manual drills).

Tips

Use the ratchet where the crank cannot turn through
Griffith and Noyes both say the ratchet brace lets the user bore near surfaces or corners where a complete sweep cannot be made. Noyes adds that it also helps where power can be applied only through part of the turn.1 2
Read the number on the tang
On an auger bit a single number on the tang is the numerator of a fraction over sixteen, giving the diameter of the hole in sixteenths of an inch. Griffith gives this rule and Noyes says the same of auger bits.1 2
Let the spur do the pulling
Noyes says it is seldom necessary to press on the knob while boring, because the screw thread on the spur pulls the bit through, especially in soft wood. As the bit nears the far face, easing the knob back lets the spur prick through and tells the user to stop.1
Finish a through hole from the second face
Both authors advise against boring a through hole entirely from one side, because the wood is splintered off on the back. When the spur pricks through, remove the bit, turn the piece over and finish from the other side, with the spur in the hole it made.1 2
Bore to depth with a stop block
Griffith gives two ways to bore a blind hole: measure the distance from the surface to the grip of the brace and stop when it has shrunk by the depth wanted, or, for many holes, cut a block as long as the exposed bit less the depth and set it beside the bit so the grip strikes it.1
Take a screwdriver bit half a turn at a time
Griffith says a screwdriver bit in a brace tends to jump out of the screw slot in hard wood; turning only half a revolution and then moving the brace slightly backward lets the bit drop back into the groove.1

History

Earliest documented

ca. 1427–32

Netherlands (workshop of Robert Campin)

In the right wing of the Mérode Altarpiece, which the Metropolitan Museum dates to about 1427–32 and attributes to the workshop of Robert Campin, the Journal of Historians of Netherlandish Art describes Joseph as handling a brace and bit. It is the earliest depiction located in this research. The Science Museum Group separately holds an iron drill of the brace and bit type dated 1501–1800.1 2 3

The earliest depiction located here is a painting and not a tool. The Metropolitan Museum dates the Mérode Altarpiece to about 1427–32, and the article by the Journal of Historians of Netherlandish Art, citing Charles Minott’s earlier finding, reads the brace and bit in Joseph’s hands together with the ax, saw and rod in the foreground as allusions to Isaiah 10:15. That the tool is shown in use in a carpenter’s workshop at that date establishes that it existed by then. The Science Museum Group’s iron drill of the brace and bit type is dated only to the broad span 1501–1800, so the surviving objects add little to the chronology.

The brace turns the bit by a crank whose sweep gives leverage, and its head lets the user press along the axis. The Millers Falls catalog of 1878 and the Stanley catalog of 1929 show how fully it had become a catalog item with sizes by sweep. Noyes’s and Griffith’s texts show it as part of school woodworking by 1908–1910, with auger bits sized in sixteenths and a ratchet for confined work.

The improvements recorded in patents concern the chuck and the ratchet. Spofford’s 1859 patent addresses the problem that every bit shank had to fit its socket exactly, and replaces the fixed socket with a slotted pair of jaws closed by a thumb screw. Barber’s 1864 patent describes jaws that center the bit and press it into the socket by their lengthwise motion. By April 1878 Millers Falls was selling Barber braces made of steel in sweep and jaws, and its catalog lists Lynam’s patent ratchet brace alongside them. Spofford’s 1881 ratchet patent shows that holding the bit in place at the start of a hole remained an open problem more than twenty years later.

Later sources place the brace among other manual drills. Stanley’s 1929 catalog lists breast drills and hand drills in sections of their own, and the 2004 U.S. military hand-tool manual treats the brace drill, breast drill and hand drill together in one chapter, describing the brace’s ratchet, chuck and fixed-size bits. The sources consulted do not measure how widely the brace is used now, and that is not asserted.

Timeline

1427–1432
The Mérode Altarpiece is painted in the workshop of Robert Campin; the article in the Journal of Historians of Netherlandish Art describes Joseph handling a brace and bit in its right wing.1 2
1501–1800
The Science Museum Group dates an iron drill of the brace and bit type, 250 mm long, to this span.1
1859
Nelson Spofford of Haverhill, Massachusetts, is granted US Patent 25,984 for a brace socket slotted into two jaws, forced together by a thumb screw so one socket holds bit shanks of differing size and bevel; the patent is reissued in 1867 as No. 2,576.1
1864
William Henry Barber of Greenfield, Massachusetts, is granted US Patent 42,827 for a chuck whose two jaws grasp the bit above the tang, center it and press it into the socket by their lengthwise motion.1
1878
Millers Falls Co. announces in its April catalog that its Barber braces are now made of steel in both sweep and jaws and heavily nickel plated at an unchanged price; the catalog also lists Barber ratchet braces, Lynam’s patent ratchet bit brace and a universal angular bit stock.1
1881
Spofford is granted US Patent 246,233 for a ratchet bit-brace with a removable rod and spring pawl, stating that previously no means had been devised to prevent the bit from backing at the moment of starting.1
1908
Griffith’s Essentials of Woodworking treats the brace or bitstock, plain and ratchet, as a standard school tool.1
1910
Noyes’s Handwork in Wood describes the brace as the holder for all sorts of boring tools and defines its size by its sweep.1
1929
The Stanley Works lists a household bit brace with an open ratchet and alligator jaws, 8-inch sweep, in its Catalogue No. 129.1

Gaps in the record (7)

No document earlier than the Mérode Altarpiece has been located for the crank-and-bit form; classical and earlier medieval evidence has not been searched.
The Science Museum Group record is a broad span (1501–1800) with no maker or place; no object dated before 1859 with a known maker has been located.
Barber’s patent is read here only in its OCR text; the relationship between Barber’s patent and Millers Falls’s production, reported in collector literature, has not been sourced to a primary document.
The 1878 Millers Falls catalog is known from poor OCR text; the patent dates printed beside the Bartholomew brace were not read reliably and are not cited.
No standard governing bit-brace chucks or bit tangs has been sourced, so standards is empty.
No typical sweep or bit capacity has been sourced for modern braces.
No published test of braces was found, so buying is null.

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