Shi Shi Tong manufactures made-to-drawing long and extra-long screws in M1.4–M12 diameters, with overall lengths up to 2000 mm subject to geometry, material, tolerance and manufacturing review. Head style, drive, thread zone, shank geometry and inspection requirements can be configured around the assembly.
Single-die cold heading, multi-station forming, open-die forming, thread rolling and selected secondary machining are evaluated according to the drawing rather than applied as one fixed process.
Drawings, samples and specifications accepted.
Long screws are threaded fasteners used when standard catalog lengths cannot provide the required reach, thread engagement, clamping zone, spacing or positioning. There is no universal length threshold: whether a screw is considered long depends on its diameter, length-to-diameter relationship, geometry and application. Search terms such as extra-long, very long or ultra-long screws generally describe the same underlying requirement: a fastener whose reach, thread engagement or geometry cannot be met by a standard catalog part.
Feasibility is confirmed from the complete combination of diameter, length, geometry, material, thread, tolerance and manufacturing route.
Compare long screw configurations by drive type, thread design, material, strength and application requirements. Length, head style, thread engagement and manufacturing route can be customized to suit your drawing and assembly conditions.
Made-to-drawing long machine screws for assemblies requiring extended reach, controlled thread engagement and custom overall length. Head style, drive, diameter, thread pitch, threaded length and material can be specified according to the application.
Long socket screws for assemblies requiring internal-hex installation, compact head geometry and extended fastening reach. Socket head dimensions, thread length, material, strength grade and surface treatment can be customized from the drawing.
Long Phillips screws designed for applications requiring extended reach and screwdriver-accessible installation. Head geometry, recess dimensions, thread specification, material and overall length can be defined according to the assembly.
Made-to-drawing long screws manufactured from selected stainless steel grades for applications requiring corrosion resistance and dimensional stability. Grade, thread, finish, forming route and machining requirements are confirmed according to project conditions.
Extra-long screws manufactured for applications with drawing-defined strength, hardness and heat-treatment requirements. Property class, base material, thread geometry, coating and mechanical performance should be evaluated together.
Extra-long self-tapping screws for applications requiring direct thread formation in sheet metal, plastic or other compatible materials. Point geometry, thread form, head style, material, coating and total length can be specified from the application requirements.
Diameter and overall length must be reviewed together.
As the length-to-diameter ratio increases, forming stability, handling and measurement become more sensitive. Diameter, overall length, shank geometry and straightness requirements should therefore be evaluated together.
Head diameter, head height, recess depth and material movement affect tooling and forming-route selection. A longer screw cannot always use the same head-forming method as a shorter catalog screw.
Full thread is useful when extended engagement or adjustment is needed. Partial thread is more suitable when the assembly requires a defined locating, bearing or clamping section. Effective thread length and measurement reference should appear on the drawing.
Heat treatment, coating thickness, handling and secondary operations can affect thread fit and final geometry. Critical datums, straightness, runout or concentricity should be defined only where they control assembly performance.
Key screw dimensions and features are evaluated according to the drawing, application and manufacturing feasibility.
M1.4–M12 diameters and lengths from 2 mm up to 2000 mm, subject to the complete geometry and manufacturing review.
Define the head diameter, height, bearing face, recess size and installation tool space. Custom or proprietary drive systems remain subject to tooling, rights and manufacturing review.
Metric or inch thread, pitch or TPI, tolerance class, full or partial thread, effective thread length, plain shank, reduced section and shoulder geometry can be evaluated according to the assembly.
Selected stainless steel, carbon and alloy steel, titanium, aluminum, copper and copper-alloy grades, including brass, can be evaluated according to the required geometry and manufacturing route.
Compare Screw Material Options →Property class 12.9 requests require review of the applicable standard, material, diameter, heat treatment, hardness or mechanical-test requirement, coating and installation conditions.
Surface-treatment coordination, coating thickness, thread-fit allowance, color, thread locking and nylon patch requirements are evaluated according to the base material and application.
Define only the dimensions that control fit and function, including datums, overall length, shoulder diameter, thread position, head or recess dimensions, straightness, runout and concentricity where applicable.
When straightness, runout or concentricity is functionally important, the drawing should define the datum, tolerance and inspection method. As screw length increases, the shaft becomes more sensitive to deformation during cold heading and thread rolling.
Secondary machining, handling, heat treatment, and surface processes can affect the final geometry. We evaluate and inspect specified straightness requirements based on your drawing.
Equipment resolution is not the same as a stable production tolerance. Acceptance criteria should be connected to the drawing, manufacturing route and agreed measurement method.
Surface treatments should be evaluated alongside material, thread fit and application conditions.
Base material, coating system, thickness, and test methods.
Pre-treatment dimensions, tolerance allowance, and GO/NO-GO inspection.
Color, texture, locking patches, or nylon application.
For coated high-strength steel, material, heat treatment, pretreatment, plating, baking requirements, thread fit and hydrogen-embrittlement risk controls should be reviewed together.
Provide these parameters for an accurate engineering review and quotation.
| Parameter | What to Define & Why It Matters |
|---|---|
| Diameter | Metric or inch nominal diameter |
| Overall Length | Clarify whether the head is included |
| Head | Style and critical head dimensions |
| Drive | Type, size, depth and tool-access requirement |
| Thread | Pitch/TPI, tolerance class and mating thread |
| Thread Coverage | Full, partial or specified threaded zones |
| Shank/Shoulder | Diameter, length, transitions and datum |
| Material | Exact grade, condition and certificate needs |
| Strength/Hardness | Standard, property class, heat treatment and test method |
| Surface Finish | Finish, thickness, color, thread allowance and test requirement |
| Critical Geometry | Datum, straightness, runout, concentricity or other functional control |
| Inspection | Gauge, measurement method, sampling and documentation |
Countersunk and semi-countersunk screw lengths commonly include the head, while many other head styles are measured from under the head. The approved drawing and applicable standard remain the final reference.
The manufacturing route is selected according to screw diameter, length, head geometry, material, thread configuration, tolerance and order requirements.
Drawing & Assembly Review
DFM, Process and Tooling Planning
Sample or First-Article Validation
Batch Production
Final Inspection & Documentation
These are selectable manufacturing and secondary-process options, not a fixed production sequence. The applicable route is determined by the screw diameter, length, head geometry, material, thread configuration and tolerance requirements.
Long screws are used where an assembly requires extended reach, defined thread engagement, component spacing or positioning beyond standard catalog dimensions.
Extended reach, defined engagement or long through-connections
Load, stack length, access and thread engagement
Controlled shank, shoulder or locating geometry
Datum, alignment, runout and installation space
Non-standard reach, corrosion requirement or special head access. Battery modules and core pack assemblies requiring extended reach, controlled installation space and drawing-defined thread engagement.
Environment, mating material, finish and inspection requirements
1998
Manufacturing Since
50+
Primary Production Machines
10+
Professional Inspection Devices
ISO 9001
Quality Management System
Head, drive, thread, shank and functional features are evaluated according to the drawing and application.
We evaluate single-die, multi-station and open-die forming processes based on your design.
We review dimensional changes, material constraints, assembly clearance and surface-treatment requirements before the final drawing is released for batch production.
Inspection of dimensions, threads, straightness, runout, and hardness determined by your drawing.
Engineering review and first-article validation establish the approved drawing, process and inspection requirements for batch production.
Examples of long-shank, specified-thread and custom-head configurations. Final specifications are evaluated for each drawing and application.
A long unthreaded shank with a defined threaded section and custom head geometry. Suitable as a reference for assemblies requiring extended reach without full-length threading.
Confirm overall length, effective thread length, shank diameter and head dimensions.
A long-shank configuration with external-hex installation. The manufacturing route can combine forming and selected secondary operations when required.
Confirm whether length is measured from under the head, along with wrench access, thread zone and end geometry.
A drawing-defined configuration with extended shank and special end geometry. DFM review and project-specific inspection are planned when the drawing defines critical requirements.
Material, finish, datums and inspection requirements are confirmed for the project.
A drawing-based development project involving changing assembly requirements, material planning, DFM review, sample validation and batch delivery.
Metric dimensions shown according to the approved customer drawing.
The customer, a U.S. battery pack and energy storage system manufacturer, required an extra-long socket head screw for a battery core pack assembly. During development, the required length changed several times, while the available installation space placed strict limits on the screw diameter and any additional insulating structure. The project also required property class 8.8 performance and practical corrosion protection for overseas transportation.
Shi Shi Tong reviewed the drawing, forming route, material requirements and assembly constraints. We proposed alternative sampling paths to manage the minimum order requirement for the target material, explained the natural forming line beneath the head, and provided a more manufacturable thread-end option for customer evaluation. The screw was designed as a one-piece formed component rather than a welded long-shank assembly.
A 1000 V insulation requirement was evaluated during development. An external insulating sleeve was not adopted because the increased outside diameter would have required changes to the customer’s mating components. The customer later removed the insulation requirement, and the final product used a standard corrosion-resistant black oxide finish without specific high-voltage insulation ratings.
After the final M6 × 272 mm drawing was confirmed, samples passed the customer’s assembly validation and the project moved into batch production. A batch shipment weighing approximately 1.49 metric tons was dispatched to the United States, packed securely for heavy international transit.
Send us your drawing, target strength, installation space and critical dimensions for a manufacturing review.
Inspection items and measurement methods are defined according to the drawing, material, process and functional requirements.
Overall and sectional dimensions
Thread GO/NO-GO inspection
Thread pitch and recess depth
Head and drive dimensions
Radius and angle
Straightness and runout when specified
Concentricity when specified
Rockwell/Vickers hardness when required
Torque testing when specified
Material verification
Project-specific inspection
Quality Management System
Tested Sample and Scope Shown in the Report
Third-Party Test Report for the Specified Sample
Environmental Compliance Testing
Material, dimensional, thread, hardness, surface-treatment and traceability records may be defined according to the drawing, order and inspection plan.
Certificates and third-party reports apply only to the company, material, sample or scope identified in the corresponding document. Project documentation is confirmed separately.
Screws with one or more defined shoulder diameters for positioning, spacing, bearing or controlled assembly.
Explore Shoulder Screws →Drawing-defined screws with non-standard heads, drives, threads, shanks, tails, materials or functional features.
Explore Custom Screws →Compare material categories, grades, manufacturing considerations and approximate density information.
Compare Screw Materials →Review surface-treatment options according to base material, thread fit, appearance and application requirements.
Compare Surface Finishes →Upload a drawing or describe the required diameter, overall length, thread configuration, head and drive, material, finish, critical dimensions and expected quantity.
Send drawing / photo / sample requirements directly to our engineers.
WhatsApp Our Engineer