Thread-forming screws

The TAPTITE 2000 brochure's MR4 × 0.7 medium-light steel-member entry gives 1.4–2.4 mm thickness, 3.64 mm pilot hole and #27 / 3.66 mm drill designation. The drill size is a separate catalog field from the pilot value. Keep the recommendation with that thread form, host and thickness. Check the actual hole and forming torque for the assembly. TAPTITE 2000 brochure, PDF page 5.

A forming screw displaces receiving material into a mating thread. TAPTITE 2000 end-user specification PR-180, PDF page 2, TAPTITE 2000 brochure, PDF page 4.

The examples use an existing receiving hole. Check pilot size, axial engagement and forming torque for the actual host. TAPTITE 2000 brochure, PDF pages 4–5, PR-180, PDF pages 7–9 and 14.

Lobular body, thread profile, and lead

TAPTITE 2000 combines a TRILOBULAR cross-section with the proprietary Radius Profile thread form. These describe different geometry: lobulation is the departure from a round cross-section, whereas the profile describes the thread tooth. The brochure further distinguishes greater out-of-round geometry in the forming-point region from reduced lobulation on the thread body. A thread-forming screw is therefore not defined by nominal diameter and pitch alone. TAPTITE 2000 brochure, PDF pages 2–3

The May 2019 revision of PR-180 specifies a four-thread tapered lead for standard TAPTITE 2000 sizes M5 and smaller. For M6 and larger it describes two stabilizing threads, a three-thread tapered lead, and dual TRILOBULAR geometry. Its introduction separately identifies the short-point SP variant for blind holes in aluminum, zinc, and magnesium and the CA variant as a hole-finding point. These are named configurations, not interchangeable meanings of “lead.” PR-180, PDF pages 2 and 4

For an exact dimensional example, the PR-180 MR6, pitch 1.00 mm body row gives C = 5.90–6.03 mm and D = 5.78–5.93 mm. C and D are the body's cross-section dimensions identified in that drawing, not receiving-hole diameters. The page expressly states that dimensions are before plating; it separately identifies ordered screw length Ls. These values do not specify a coating allowance, stock length, or current drawing for an individual supplied part. PR-180, PDF page 4

Receiving material and heat treatment

PR-180 separates three heat-treatment routes rather than assigning one condition to all TAPTITE 2000 screws. Its standard small-size steel configuration is case hardened; CORFLEX-I uses neutral hardening with a selectively induction-hardened forming point; CORFLEX-N is neutral, or through, hardened for soft metals such as aluminum, zinc, and magnesium. The screw's forming region and its load-carrying body can consequently have different treatment functions. PR-180, PDF pages 2, 7, 10 and 14

The case-hardened and CORFLEX-I sections each state an intended receiving-steel scope of up to 250 HV. That scope limit is not the hardness of their test plate, nor does it establish suitability for every steel at that hardness. The case-hardened forming-test description instead uses low-carbon steel at 115–150 HV30. The CORFLEX-N test description uses an aluminum plate at HB 30–75. The different scales and material descriptions belong to their respective test contexts. PR-180, PDF pages 7, 9, 10 and 16

The case-hardened section describes carburizing or carbonitriding, quenching, and tempering. Surface condition is a separate variable: the brochure's torque data use zinc-plated, waxed screws, while PR-180 allows lubricant in its case-hardened thread-forming capability test. Neither a heat-treatment name nor a nominal strength designation alone reproduces those friction and forming conditions. PR-180, PDF pages 7–8, TAPTITE 2000 brochure, PDF page 10

Pilot diameter, drill designation, and engagement

The brochure uses percentage thread engagement as a radial thread-profile measure. Its MR5 × 0.8 example associates a 4.58 mm pilot hole with 80% engagement. It explicitly says its hole-versus-percentage relationship is linear and becomes less accurate below 70% engagement. Those percentages are the source's geometric approximation, not percentages of joint strength or screw length. TAPTITE 2000 brochure, PDF page 4

Axial engagement is a separate quantity. The next table groups steel-member thickness relative to nominal screw diameter under its own “application duty class” headings. Thus a radial percentage, a member thickness, and the length occupied by full-form versus lead threads describe different aspects of engagement. A single percentage does not establish the full load-bearing length in a blind or through hole. TAPTITE 2000 brochure, PDF pages 3–5, PR-180 lead drawing, PDF page 4

Pilot diameter and drill designation also differ. In the brochure's MR4 × 0.7, medium-light steel-member entry, the thickness range is 1.4–2.4 mm, the pilot-hole value is 3.64 mm, and the listed drill is #27 / 3.66 mm. The adjacent values illustrate why a nominal tool designation is not itself a measured-hole tolerance. This is a bounded catalogue entry, not a universal pilot-hole recommendation for an M4 screw. TAPTITE 2000 brochure, PDF page 5

Forming, tightening, removal, and failure torque

The brochure's torque table treats thread-forming torque, first-removal prevailing torque, recommended assembly torque, and failure torque as separate results. One selected row is reproduced below to make those distinctions concrete. Every torque value is in N·m; the dimensions are in millimetres. TAPTITE 2000 brochure, PDF page 10

The stated laboratory conditions are hex-flange heads, zinc plating plus wax, low-speed driving, cold-rolled steel test plates, and plain flat steel washers under the heads to absorb tightening. The row's asterisk indicates probable nut-thread stripping; the table uses a different mark for probable screw breakage. The first-removal value concerns rotation after the head has been unseated. It is not the head breakaway torque, the forming torque, or a guarantee of repeated use. TAPTITE 2000 brochure, PDF page 10 and notes

PR-180 describes a different kind of evidence in its case-hardened thread-forming capability test: formation of a full-major-diameter internal thread through the plate, no screw-thread deformation, and a formed thread capable of accepting a standard 6g machine screw. Its stated driving-speed ceiling is 300 rpm, recording maximum forming torque is optional, and lubricant is permitted. That capability test is distinct from the brochure's assembly-torque recommendation and from an installed joint's strength or clamp-load requirement. PR-180, PDF pages 8–9

Source versions and limits

The inspected end-user specification is PR-180, January 2008, revised May 2019, with a separate 2013 copyright notice. The brochure also prints copyright 2013; its download filename mentions a table correction dated October 16, 2019, but that filename is not an established printed edition date. Both files were accessed on October 31, 2026 (PDT) from the REMINC/CONTI product site's linked downloads. PR-180 cover, PDF page 1, brochure, PDF page 12, REMINC/CONTI TAPTITE 2000 page

The brochure labels its tables as guidance, and PR-180's material sections distinguish their product requirements from specific applications. These sources do not establish a universal hole size, tightening torque, reuse allowance, or customer qualification. The full referenced ISO, SAE, and ANSI standards were not independently accessed; their names in a manufacturer document do not establish inspection of those editions or conformity of an unspecified supplied screw. Brochure, PDF pages 4 and 12, PR-180, PDF pages 7, 10 and 14

Related reference

Hardware and component references covers the broader assembly-process context.