For half-round head wood screws, gost 1144 (types 1–4) in A4 Stainless Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) is summarized below together with every size supplied.
Why Choose A4 Stainless Steel for Half-Round Head Wood Screws, GOST 1144 (Types 1–4)
Specified for marine, coastal and chemical applications. For half-round head wood screws, gost 1144 (types 1–4), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Half-Round Head Wood Screws, GOST 1144 (Types 1–4) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
Two important notes for stainless half-round head wood screws, gost 1144 (types 1–4): (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Using Stainless Fasteners in Aluminum
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Half-Round Head Wood Screws, GOST 1144 (Types 1–4) Available in A4 Stainless Steel
| Size | Type | d2 (mm) | Pitch P (mm) | D (mm) | Head height k (mm) | b (mm) | h (mm) | Cross recess size | m (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1.6 mm | (Type 1) Half — round head wood screw | 1.1 | 0.8 | 3.2 | 1.1 | 0.4 | 0.6 | 7~13 | GOST 1144 | ||
| 2 mm | (Type 1) Half — round head wood screw | 1.4 | 1 | 4 | 1.4 | 0.5 | 0.9 | 7~16 | GOST 1144 | ||
| 2.5 mm | (Type 1) Half — round head wood screw | 1.7 | 1.25 | 5 | 1.7 | 0.6 | 1.1 | 7~25 | GOST 1144 | ||
| 3 mm | (Type 1) Half — round head wood screw | 2.1 | 1.25 | 6 | 2.1 | 0.8 | 1.2 | 10~30 | GOST 1144 | ||
| 3.5 mm | (Type 1) Half — round head wood screw | 2.4 | 1.5 | 7 | 2.4 | 0.8 | 1.5 | 10~40 | GOST 1144 | ||
| 4 mm | (Type 1) Half — round head wood screw | 2.8 | 1.75 | 8 | 2.8 | 1 | 1.8 | 13~60 | GOST 1144 | ||
| 5 mm | (Type 1) Half — round head wood screw | 3.5 | 2 | 10 | 3.5 | 1.2 | 2.3 | 13~70 | GOST 1144 | ||
| 6 mm | (Type 1) Half — round head wood screw | 4.2 | 2.5 | 12 | 4.2 | 1.6 | 2.5 | 18~100 | GOST 1144 | ||
| 8 mm | (Type 1) Half — round head wood screw | 5.6 | 3.5 | 16 | 5.6 | 2 | 3.5 | 50~100 | GOST 1144 | ||
| 10 mm | (Type 1) Half — round head wood screw | 7 | 4.5 | 20 | 7 | 2.5 | 4 | 80~100 | GOST 1144 | ||
| 1.6 mm | (Type 2) Half — round head wood screw | 1.1 | 0.8 | 3.2 | 1.1 | 0.4 | 0.6 | 7~13 | GOST 1144 | ||
| 2 mm | (Type 2) Half — round head wood screw | 1.4 | 1 | 4 | 1.4 | 0.5 | 0.9 | 7~16 | GOST 1144 | ||
| 2.5 mm | (Type 2) Half — round head wood screw | 1.7 | 1.25 | 5 | 1.7 | 0.6 | 1.1 | 7~25 | GOST 1144 | ||
| 3 mm | (Type 2) Half — round head wood screw | 2.1 | 1.25 | 6 | 2.1 | 0.8 | 1.2 | 10~30 | GOST 1144 | ||
| 3.5 mm | (Type 2) Half — round head wood screw | 2.4 | 1.5 | 7 | 2.4 | 0.8 | 1.5 | 10~40 | GOST 1144 | ||
| 4 mm | (Type 2) Half — round head wood screw | 2.8 | 1.75 | 8 | 2.8 | 1 | 1.8 | 13~60 | GOST 1144 | ||
| 5 mm | (Type 2) Half — round head wood screw | 3.5 | 2 | 10 | 3.5 | 1.2 | 2.3 | 13~70 | GOST 1144 | ||
| 6 mm | (Type 2) Half — round head wood screw | 4.2 | 2.5 | 12 | 4.2 | 1.6 | 2.5 | 18~100 | GOST 1144 | ||
| 2 mm | (Type 3) Half — round head wood screw | 1.4 | 1 | 4 | 1.4 | 1.2 | 0 | 2 | 7~16 | GOST 1144 | |
| 2.5 mm | (Type 3) Half — round head wood screw | 1.7 | 1.25 | 5 | 1.7 | 1.3 | 1 | 2.6 | 7~25 | GOST 1144 | |
| 3 mm | (Type 3) Half — round head wood screw | 2.1 | 1.25 | 6 | 2.1 | 1.7 | 1 | 3 | 10~30 | GOST 1144 | |
| 3.5 mm | (Type 3) Half — round head wood screw | 2.4 | 1.5 | 7 | 2.4 | 1.8 | 2 | 4.1 | 10~40 | GOST 1144 | |
| 4 mm | (Type 3) Half — round head wood screw | 2.8 | 1.75 | 8 | 2.8 | 2.2 | 2 | 4.6 | 13~60 | GOST 1144 | |
| 5 mm | (Type 3) Half — round head wood screw | 3.5 | 2 | 10 | 3.5 | 2.8 | 2 | 5.2 | 13~70 | GOST 1144 | |
| 6 mm | (Type 3) Half — round head wood screw | 4.2 | 2.5 | 12 | 4.2 | 3.2 | 3 | 7 | 18~100 | GOST 1144 | |
| 8 mm | (Type 3) Half — round head wood screw | 5.6 | 3.5 | 16 | 5.6 | 4.6 | 3 | 8.2 | 50~100 | GOST 1144 | |
| 10 mm | (Type 3) Half — round head wood screw | 7 | 4.5 | 20 | 7 | 5.6 | 4 | 10.6 | 80~100 | GOST 1144 | |
| 2 mm | (Type 4) Half — round head wood screw | 1.4 | 1 | 4 | 1.4 | 1.2 | 0 | 2 | 7~16 | GOST 1144 | |
| 2.5 mm | (Type 4) Half — round head wood screw | 1.7 | 1.25 | 5 | 1.7 | 1.3 | 1 | 2.6 | 7~25 | GOST 1144 | |
| 3 mm | (Type 4) Half — round head wood screw | 2.1 | 1.25 | 6 | 2.1 | 1.7 | 1 | 3 | 10~30 | GOST 1144 |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. A non-standard screw is quoted from the drawing; where one already exists in the catalog, the special is usually a variation on its tooling. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
