Nickel-free

Definition and Overview

Nickel-free is a specification that indicates consideration for nickel in the material or surface treatment of metal accessories. Nickel is considered one of the causes of metal allergies, so it is considered for clothing and fashion accessories that are likely to come into contact with the skin.

However, this label does not guarantee that no nickel is contained in any parts, or that no allergic reaction will occur in all people. Confirm the target parts and verification method in the supplier's specification sheet.

Material and Component Combinations

Press fasteners are made up of multiple metal parts, such as the outer cap, socket side, stud side, and back stud. Eyelet washers may also combine the eyelet body and washer. When nickel-free is required, it is important to check not only the visible parts but the entire set of components.

Some products use a nickel-free surface treatment on base materials such as brass, iron, and zinc alloy. On the other hand, because the base material, undercoat for plating, finish, and spring section may use different materials, the appearance color alone cannot be used to judge.

• The items to confirm are all parts that make up the product, such as the cap, spring, stud, eyelet, and washer.
• Nickel-free and no nickel plating do not necessarily mean the same thing.
• Also confirm how the product is handled if the base material becomes exposed due to wear or scratches in the plating.

How Sizes Are Shown and How They Are Attached

The size of a press fastener is generally indicated by the outer diameter of the cap or by a standard number. Eyelet washers are indicated by inner diameter, outer diameter, leg length, and so on, but the notation method varies by product. The premise is that it is combined with a mating part of the same standard.

For attachment, use a setting tool compatible with the part and a hand press or press machine. If the shape of the setting tool or the pressing force does not match, it can cause deformation, insufficient crimping, poor opening and closing, or surface scratches. Perform a test setting, then check tensile strength and opening/closing before moving to mass production.

Main Uses and Selection Notes

Nickel-free specifications are considered for shirts, baby and kids' clothing, innerwear, and fasteners for accessories that easily touch the skin directly or nearby. Depending on the application, also select the required holding strength, number of opening and closing cycles, and resistance to washing and perspiration.

If the textile is thin, excessive pressing force or leg length of the part can easily damage the textile, while in thick textiles, if the leg length is insufficient, it cannot be crimped properly. For stretch textiles and open weaves, check pull-out strength, including reinforcement with a pressing cloth or interfacing.

• Select a leg length that matches the fabric thickness and the thickness after compression.
• Evaluate corrosion and discoloration according to the usage environment, such as washing, sweat, friction, and seawater.
• For products that use metal detectors, even if they are nickel-free, confirm needle detector compatibility, taking into account that they are metal accessories.

Differences from Similar Terms

Nickel-free is mainly a material or surface-treatment specification that indicates consideration for nickel. Brass and nickel silver are names of metal materials, and whether something is nickel-free cannot be determined from the material name alone. Plating refers to the surface treatment itself, while nickel-free is a condition related to its formulation and structure.

Needle detector compatibility is a specification related to suitability for processes that detect foreign matter such as broken needles. Even if a metal accessory is nickel-free, that does not mean it is needle detector compatible.

Frequently Asked Questions

If it is nickel-free, will metal allergies not occur?

It is a specification intended to limit exposure to nickel, but it does not guarantee that no allergic reaction will occur. Physical constitution varies from person to person, and other metals, sweat, and friction also have an effect. Confirm the target parts, whether testing was performed, and the basis for the labeling with the supplier before adoption.

Can nickel-free press fasteners be attached with a standard setting tool?

They may be usable if the parts have the same shape and standard, but using the setting tool specified for the product is basic. The proper pressing force changes depending on the dimensions and material of the parts. Before mass production, test them on the actual textile and confirm the crimped condition and holding strength.

Are nickel-free and needle detector compatible the same thing?

No, they are not the same. Nickel-free is a specification related to the use or release of nickel, while needle detector compatibility is a specification related to handling in the needle detection process. For metal press fasteners and eyelet washers, both conditions need to be checked separately.