Bolts 4×20 aisi 316 – code: a4-933-04×020 – Osculati

4×20 bolts in AISI 316 stainless steel Osculati (code a4-933-04×020)

I 4×20 bolts in AISI 316 stainless steel Osculati are a bolting solution designed for those working in technical fields who want a reliable component for assemblies, replacements, and maintenance interventions. The product is identified by the supplier code a4-933-04×020, useful for reordering and maintaining consistency in spare parts warehouse management.

The type indicated by the manufacturer corresponds to the standard UNI 5739 / DIN 933, commonly associated with bolts with a hexagonal head with full threading. This size is widespread in many hardware and system applications because it allows practical tightening with common tools and simple matching with compatible nuts and washers.

Features and construction details

These bolts are made of AISI 316 stainless steel, a material often chosen in contexts where stainless steel hardware is preferred to reduce the need for frequent replacements and to maintain a neat appearance of the installation over time. In the nautical field and onboard systems, the choice of stainless steel is typically linked to the search for components suitable for working in demanding environments.

Format and identification

• Format: 4×20 (as per product name).
• Material: AISI 316 stainless steel.
• Declared type: UNI 5739 / DIN 933 (manufacturer's indication).
• Head: hexagonal (as per existing description).
• , a material commonly used in fittings and small parts for systems. The choice of brass is often linked to the need to use components compatible with other elements of the same material and with typical hydraulic configurations. complete (as per existing description).
• Supplier: Osculati S.r.l.
• Supplier product code: a4-933-04×020.

Why the hex head is a practical choice

The hexagonal head is one of the most used sizes in technical bolting because it allows working with commonly used wrenches and sockets. In maintenance, this translates into more streamlined operations: disassembly and reassembly are immediate, especially when working on already installed components or in spaces where it is important to apply the tightening torque in a controlled way (without going into specific values, which depend on the application).

Full threading: when it is useful

The full threading is often preferred when you want to maximize the adjustment possibility during assembly or when the matching with nut and washer requires a threaded portion along the entire useful length of the bolt. It is a common configuration for general fastenings and many replacement applications, where dimensional compatibility is a key requirement.

Typical applications (nautical and plant engineering)

These bolts can be used in numerous situations where mechanical fastening with stainless steel bolts is required. Actual use always depends on the project, the paired materials, and operating conditions.

Maintenance and spare parts onboard

• Replacement of existing bolts during routine maintenance interventions.
• Restoration of fastenings on accessories and onboard components that require hex head bolts.
• Spare parts management: the Osculati code facilitates the identification of the correct component during reordering.

Hardware for installations and assemblies

• Mechanical assemblies where it is preferable to use bolting in AISI 316.
• Installations requiring fastening with nut/washer, consistent with the type DIN 933 indicated.
• Interventions on systems and supports, when the 4×20 size matches the hole and material thickness.

Usage and installation notes

To achieve correct assembly, it is important to verify the consistency between bolt, hole, and mating components. Below are some general guidelines, useful as an operational reminder.

Checks before installation

• Dimensional check: make sure the 4×20 size is suitable for the material thickness and the type of fastening intended.
• Coupling with nuts/washers: choose compatible components for pitch and size, based on the application.
• Material consistency: evaluate the set of bolts and paired metals to maintain a homogeneous installation.

Good maintenance practices

• In case of replacement, always compare the removed bolt with the spare to avoid differences in size or type.
• If the fastening is subject to vibrations or stresses, consider adopting appropriate locking solutions (according to the project and maintenance procedures).
• Keep the reference a4-933-04×020 in the onboard documentation or spare parts list to speed up reorders.

Important note

The above indications are generic. For critical applications or those subject to specific requirements, refer to the procedures of the plant/equipment manufacturer and the good installation practices provided for your configuration.

FAQ – Frequently Asked Questions

What is the material of these Osculati bolts?

They are made of AISI 316 stainless steel, as indicated in the product name.

What type of bolt is it (reference standard)?

The manufacturer classifies them under the UNI 5739 / DIN 933 type, commonly associated with hex head bolts with full threading.

What is the purpose of the code a4-933-04×020?

It is the product code from the Osculati supplier: it helps identify the correct spare part and simplifies reordering and warehouse management.

Are they suitable for nautical maintenance and onboard plant engineering?

Yes, they are indicated as replacement solutions and for maintenance interventions in the nautical field and onboard systems, where stainless steel hardware is preferred.

What should I check before installation?

Check that the 4×20 size is consistent with the hole and thicknesses, and verify the matching with compatible nuts and washers based on the application.