Our History

Known as ITW Shakeproof Industrial today, the company is the result of a 2010 merger of ITW businesses that have a long, rich history in the industrial fastener market. This history dates to the 1920s, when two of ITW Shakeproof Industrial’s main product lines were created.

Shakeproof was formed in 1923 when it introduced the Twisted Tooth Lock Washer.

Rein Leitzke, established in 1929, was created through the merger of well-known fastener manufacturers Medalist Rein Leitzke and Hobbs.

Together, these companies have decades of problem solving, product design, and manufacturing experience, which is demonstrated in the quality of the products you receive.

  • 1923

    Shakeproof was formed with the introduction of the Twisted Tooth Lock Washer, addressing the need to prevent bolted joints from loosening by using friction

  • 1929

    Rein Leitzke Incorporated was established in Hustisford, WI as a manufacturer of various pins and washers

  • 1948

    25 Year Anniversary

  • 1950

    SEMS Machine Screw, first screw to captivate a washer under the screw head, was created and patented

  • 1967

    TEKS Metal Thread Forming Screw designed and patented ensures all voids and material thicknesses are accounted for

  • 1969

    Hi-Lo Plastic Thread Forming Fasteners was designed and patented to address performance challenges of fastening in low pressure environments (plastic, particle board, Masonite, etc.)

  • 1971

    Rein Leitzke was purchased by Medalist Industries, forming Medalist Leitzke

    To improve thread engagement and joint strength the GX Self-Extruding Metal Thread Forming Screw created and patented

  • 1973

    50 Year Anniversary

  • 1985

    Tap/R Metal Thread Forming Fasteners engineered and patented to roll their own perfect mating threads in an un-threaded pilot hole

  • 1987

    Square Cone Washer created and patented to provide a reliable low-torque, controlled-tension fastener

  • 1989

    Mellowes Company acquired by ITW and became ITW Shakeproof

  • 1996

    Rein Leitzke was purchased by ITW

  • 1998

    Bee Industries, manufacturer of pins and stampings (Watertown, WI) was acquired by ITW

  • 1998

    75 Year Anniversary

  • 1998

    Bee & Rein facilities merge and became ITW Bee Leitzke

  • 2000

    Hobbs Fasteners, pin manufacturer, is acquired

  • 2000

    AlignRite created and patented

  • 2002

    Facility in Iron Ridge, WI is acquired for all shipping and warehousing activities

    Hobbs facility in Worcester, MA was closed and work was moved to Hustisford and Watertown, WI

  • 2004

    Innovative Plastic Thread Forming Fastener, BosScrew, engineered and patented. This is the only screw engineered to not loosen in plastic application

    SinuLOC Machine Screw patented, providing a reusable thread forming specialty machine screw with locking threads

  • 2009

    ITW Bee Leitzke joined ITW Shakeproof, forming ITW Shakeproof Group

    Current facilities in Milwaukee, Iron Ridge, Hustisford, Watertown, Machesney Park, and Broadview

  • 2010

    Hustisford plant was closed. All jobs moved to Watertown or Milwaukee

  • 2014-2015

    Machesney Park becomes strictly automotive based and Watertown becomes Industrial based

  • 2017

    Became known as ITW Shakeproof Industrial

  • 2018

    GripTide™ patented as a low-cost steel insert for plastics that surpasses brass inserts in quality, cost, and performance

  • 2021

    Operations in Wisconsin (Watertown, Milwaukee, & Iron Ridge) and Illinois (Broadview)