Auto tc 4.2×19 aisi 316 domed – code: a4-7981-04.2×019 – Osculati

Self-tapping screw in AISI 316 stainless steel Osculati (Auto TC 4.2×19) – pan head

The Osculati self-tapping screw in AISI 316 stainless steel with rounded head and cross recess is a hardware solution designed for technical applications where practical, neat, and consistent fastenings with the stainless steel hardware already on board are needed. The format 4,2×19 makes it suitable for numerous assembly and maintenance applications on appropriate supports, in nautical and plant engineering fields.

The product is identified by the supplier code a4-7981-04.2×019 (Osculati S.r.l.) and reports as references the standards UNI 6954 / DIN 7981 indicated by the manufacturer. In a professional context, being able to rely on a clear and repeatable reference helps maintain uniformity in the choice of screws and simplifies procurement activities.

Features and construction details

Material: stainless steel AISI 316

The screw is made of AISI 316, , a stainless steel alloy commonly chosen in the nautical field for its suitability in exposed environments and for compatibility with many onboard applications. When selecting small hardware, using stainless steel screws consistent with the rest of the fittings helps to manage spare parts and maintenance more orderly.

Type: self-tapping

Being a self-tapping screw, is designed to create its own thread in the supporting material during screwing, when used on suitable supports and with proper hole preparation. This feature is often useful in installations where a quick and practical fastening is desired, reducing preliminary operations compared to solutions that require pre-existing threads.

Domed head and cross recess

The rounded head offers a clean look and a neat visual finish, making it suitable when the screw head remains visible and a rounded profile is desired. The ’cross recess allows the use of common tools and facilitates assembly and disassembly operations during maintenance.

Size 4.2×19

The size 4,2×19 is suitable for many small hardware and fittings applications, especially in installations where a compact fastening is required. The correct size choice should always be made based on the thickness of the materials, the type of support, and the expected operating conditions.

Regulatory references indicated by the manufacturer

The manufacturer provides the following references UNI 6954 and DIN 7981. These indications are useful for those who want to maintain consistency with industry standards in screw selection and replacement of existing components.

Product identification

• Supplier: Osculati S.r.l.
• Supplier product code: a4-7981-04.2×019

Typical applications (nautical and onboard plant engineering)

This stainless steel self-tapping screw can be used in many situations of installation and maintenance where reliable and easily available small hardware is required, with a finish suitable for technical and marine contexts. In particular, it is often chosen for:

• Onboard hardware and accessories: fastening small components, brackets, supports, and small hardware where the head remains visible and a neat appearance is desired.
• Plant engineering: light assemblies and fastening of accessory elements on suitable supports, in technical areas or plant compartments.
• Restoration interventions: replacement of existing screws maintaining material consistency (AISI 316 stainless steel) and type (self-tapping).
• Fittings and refitting: updating or organizing screwwork, where traceability through code and standard references helps manage stock.

For specific applications on particular materials or in the presence of design constraints, it is good practice to verify in advance the compatibility of the support and the correct installation procedure.

Usage and operational notes

Hole and support preparation

For a correct result, it is advisable to pay attention to the hole preparation based on the material and thickness of the support. Proper preparation can help achieve smoother screwing and reduce the risk of damage to the support or screw during installation.

Tightening and tools

Use a tool suitable for the ’cross recess and apply controlled tightening, avoiding forcing. In case of repeated assemblies or frequent maintenance, it is useful to periodically check the condition of the drive and the fastening seat.

Good practices in a nautical environment

In marine environments, it is good practice to keep hardware clean and inspectable, especially in exposed areas. When replacing, choosing screws of the same material (such as the’AISI 316) helps maintain consistency with the existing installation and simplifies component management.

Note on standards and identification

When working on systems or setups where uniformity is required, the references UNI 6954 / DIN 7981 and the product code are useful elements to compare and replace screws more straightforwardly, without introducing unnecessary variants.

FAQ – Frequently Asked Questions

What is the material of the Osculati self-tapping screw?

The screw is made of AISI 316 stainless steel, as indicated in the product description.

What type of head and recess does this screw have?

It is a screw with a pan head and cross recess, suitable for assemblies and maintenance with common tools.

What is the size of the screw?

The indicated size is 4.2×19.

What is the product code from the Osculati supplier?

The supplier product code is a4-7981-04.2×019.

Are there references to industry standards?

Yes. The manufacturer reports the UNI 6954 and DIN 7981 references.