# US 9,518,599 B2 · Metal to metal fastener > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,599 B2 - Document ID: US9518599B2 - Status: Granted - Kind: B2 - Application number: 14/249,943 - Filed: 2014-04-10 - Published: 2015-10-15 - Granted: 2016-12-13 - Earliest claimed: 2014-04-10 - Assignees: Simpson Strong-Tie Company, Inc. - Applicants: Simpson Strong-Tie Company, Inc. - Inventors: Neelima Tapata - Web page: https://patentgrep.com/patent/US9518599B2 ## CPC - F16B 35/04: with specially-shaped head or shaft in order to fix the bolt on or in an object (locking the bolt against turning in the object by the use of accessory parts F16B39/00) - E04D 3/3606: {the fastening means being screws or nails} - F16B 23/00: Specially shaped {nuts or} heads of bolts or screws for rotations by a tool {(detachable ornamental heads for screws A47G3/00; screwdrivers, wrenches B25B)} - F16B 25/103: {by means of a drilling screw-point, i.e. with a cutting and material removing action} - F16B 43/00: Washers or equivalent devices; Other devices for supporting bolt-heads or nuts (circlips F16B21/18; {for indicating tensile load F16B31/02; forming a whole with the bolt or nut F16B33/00; locking bolts or nuts by means of a fixed plate or ring, or washer-like resilient plates F16B39/10, F16B39/24}) - F16B 25/0021: {the material being metal, e.g. sheet-metal or aluminium (F16B25/0031 takes precedence)} - F16B 25/0084: {characterised by geometric details of the tip} - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) - E04D: ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS (coverings of outer walls by plaster or other porous material E04F13/00) ## Abstract A fastener includes a shank having a diameter including a helical thread and a cutting tip. The fastener includes a head having an integral washer and nut. The washer has a diameter (d) and a thickness (t), wherein a relation of the diameter to the thickness is established through a shape factor greater than 0.55, the shape factor for the thickness (t) greater than 0.06 inches being d*(1+2.5t)*t(t-0.06) and for the thickness (t) less than or equal to 0.06 inches being d*(1+2.5t)*t(0.06-t). The fastener may be used in a system wherein a thin steel element abuts the washer and the fastener joins the thin steel element to a thick steel element. ## Claims ### Claim 1 A fastener, comprising: a shank having a point at a first end and a second end defining a length, the shank including a first section and a second section, the second section including a plurality of threads and having a shank diameter, the second section adapted to engage a first steel element and a second steel element having a thickness greater than the first steel element, a head having an integral washer adapted to engage the first steel element, the washer having a washer diameter (d) and a thickness (t), wherein a shape factor of the washer describes a combined effect of the diameter and the thickness, wherein the shape factor for the thickness (t) greater than 0.06 inches is d*(1+2.5t)*t(t-0.06) and for the thickness (t) less than or equal to 0.06 inches is d*(1+2.5t)*t(0.06-t), and wherein the shape factor is greater than 0.55 to thereby provide improved shear resistance when attaching a first material having a thickness to a second material having a greater thickness. ### Claim 2 (depends on 1) The fastener of claim 1 wherein the first section includes a cutting tip. ### Claim 3 (depends on 2) The fastener of claim 2 wherein the thickness of the washer is between 0.1 inch and 0.05 inch. ### Claim 4 (depends on 3) The fastener of claim 3 wherein the thickness of the washer is 0.06 inch. ### Claim 5 (depends on 1) The fastener of claim 1 wherein the diameter of the washer is between 0.75 and 0.5 inch. ### Claim 6 (depends on 5) The fastener of claim 5 wherein the diameter of the washer is 0.625 inch. ### Claim 7 A system, comprising: a first steel element having a first thickness; a second steel element having a second thickness greater than the first thickness; and a fastener joining the first steel element to the second steel element, the fastener including a shank having a shank diameter and a head having an integral washer, the washer having a washer diameter (d) and a washer thickness (t), wherein a shape factor of the washer describes a combined effect of the diameter and the thickness, wherein the shape factor for the thickness (t) greater than 0.06 inches is d*(1+2.5t)*t(t-0.06) and for the thickness (t) less than or equal to 0.06 inches is d*(1+2.5t)*t(0.06-t), and wherein the shape factor is greater than 0.55 to thereby provide improved shear resistance when attaching a first material having a thickness to a second material having a greater thickness. ### Claim 8 (depends on 7) The fastener of claim 7 wherein the washer abuts the first steel element. ### Claim 9 (depends on 7) The fastener of claim 7 wherein the second thickness is at least two and half times the first thickness. ### Claim 10 (depends on 7) The fastener of claim 7 wherein the fastener includes a cutting tip at an end of the shank opposing the head. ### Claim 11 (depends on 10) The fastener of claim 10 wherein the washer thickness is between 0.1 inch and 0.05 inch. ### Claim 12 (depends on 11) The fastener of claim 11 wherein the washer thickness is 0.06 inch. ### Claim 13 (depends on 11) The fastener of claim 11 wherein the washer diameter is between 0.75 and 0.5 inch. ### Claim 14 (depends on 11) The fastener of claim 11 wherein the washer diameter is 0.625 inch. ### Claim 15 A system, comprising: a first steel element having a first thickness; a second steel element having a second thickness at least two and half times the first thickness; and a fastener joining the first steel element to the second steel element, the fastener including a shank having a point at a first end defining a cutting point and a head at a second end defining a length, the shank including a first section and a second section, the second section having a shank diameter and a helical thread thereabout, a head positioned adjacent to the helical thread having an integral washer, the washer having a washer diameter (d) and a thickness (t), wherein a shape factor of the washer describes a combined effect of the diameter (d) and the thickness (t), wherein the shape factor for the thickness (t) greater than 0.06 inches is d*(1+2.5t)*t(t-0.06) and for the thickness (t) less than or equal to 0.06 inches is d*(1+2.5t)*t(0.06-t), and wherein the shape factor is greater than 0.55 to thereby provide improved shear resistance when attaching the first steel element to the second steel element, and the washer abuts the first steel element. ### Claim 16 (depends on 15) The system of claim 15 wherein stress failure occurs under type II AISI bearing failure.