Irwin Auger Bit Company: Markings and Sets

This page describes the stamps that the Irwin Auger Bit Company used on its bits and the sets of carpenters' bits it marketed. The report covers the years 1887 through 1983 and is based on five Irwin catalogs, ten examples of the company's How to Select, Use and Care for Bits booklets, a dozen ads in hardware publications, thirty-two sets of Irwin bits, and photos from 14,501 on-line auction transactions.

The information presented is comprehensive, rather than complete, and despite the herculean effort involved in putting it together, new bit stamps and assortments of carpenters' bits pop up from time to time.

an Irwin auger bit

Bit Marking (not to scale)

1887-ca. 1894 bit stamp

earliest irwin bit stamp

1894-ca. 1900 bit stamp

second irwin bit stamp

ca. 1900-ca. 1904 bit stamp

third irwin bit stamp

ca. 1904-1907 bit stamp

slanted irwin bit stamp

1907-ca. 1914 bit stamp

After the original Irwin patents expired, the company trademarked the Irwin name to prevent imitators from using it.

first irwin patent office bit stamp

ca. 1914-ca. 1917 bit stamp

quoted irwin bit stamp

ca. 1917-1923 bit stamp

unquoted irwin bit stamp

1923-ca. 1930 bit stamp

first irwin borfamily bit stamp

ca. 1930-1937 bit stamp

second irwin borfamily bit stamp

ca. 1938-ca. 1948 bit stamp

irwin bit stamp, no patent office

ca. 1948-1951 bit stamp

IRWIN - U S OF A

1951-ca.1960 bit stamp

IRWIN - U. S. A.

ca. 1961-ca. 1966 bit stamp

irwin double bar bit stamp

ca. 1966-ca. 1983 bit stamp

second U S OF A irwin bit stamps

ca. 1983-19?? bit stamp

bit stamp with size number

 

a Bluwin bit

 

Sets of Bits

1892-1893 Cylindrical Case

1892-ca. 1900 Model Case (type 1)

ca. 1900-ca. 1904 Model Case (type 2)

ca. 1905-ca. 1918 Model Case (type 3)

ca. 1905-1923 Roll

ca. 1918-ca. 1923 Model Case (type 4)

ca. 1918-1923 Model Case (type 4B)

1923-1932 Borchest (Model Case 4C)

1923-ca. 1936 Borcases

1923-ca. 1936 canvas Borkit

1924-1933 Bench Set

1932 BLUWIN Borchest (Model Case type 4C)

1933-ca. 1936 "fair competition" Borchest

ca. 1936-ca. 1939 "Genuine Irwin" Borchest

1937-ca. 1947 leatherette Borkit

ca. 1939-ca. 1941 "glossy liner" Borchest

ca. 1941-ca. 1947 "no liner" Borchest

U. S. Navy bits with unpolished stems

ca. 1947-ca. 1951 "black stamp" Borchest

ca. 1951-ca. 1956 Borchest

draw latch

ca. 1957-ca. 1959 "minimal paper" Borchest

ca. 1957-ca. 1959 minimal paper borchest

ca. 1959-ca. 1977 Borchest

ca. 1977-ca. 1983 Borchest

type 2 draw latch

ca. 1983-19?? "red liner" Borchest

full-size red-liner borchest, ca. 1959-ca. 1977

Later variations of the "red liner" Borchest have not been studied.

ca. 1976-ca. 1980 Variants

ca. 1966-ca. 1980 "expansive bit" Borchest

expansive bit Borchest

ca. 1976-ca. 1980 "steel" Borchest

Irwin bit set in steel case