Continuous (Piano) hinges -Specification

IS 3818: Scope & Key Specifications for Continuous (Piano) Hinges

Scope:

• Covers continuous (piano) hinges used in doors, panels, and furniture.
• Specifies materials, dimensions, tolerances, marking, packing, and sampling criteria.

Key Specifications:

1. Materials (Table 1)

• Hinges made from materials conforming to IS 513:1986 Grade D (cold-rolled low carbon steel sheets).
• Other materials as per related IS standards (e.g., IS 280, IS 737, IS 739).

2. Dimensions & Tolerances

• Types I, II, III, IV hinges dimensions as per Figs. 1, 2, 3.
• Length multiples: Usually in multiples of 304 mm.
• Minimum screw hole distance from flap end:

  Nominal Size (mm)	Distance (mm)
  25	2.0
  30	3.5

3. Packing (Clause 8.2)

• Boxes must be labeled with:
  • Manufacturer's name
  • Hinge type and size
  • Quality grade

4. Sampling & Conformity (Annex B)

• Sampling based on lot size:

Summary Diagram of Sampling Criteria

flowchart TD
    A[Lot Size] --> B{Lot Size Range}
    B -->|Up to 150| C[Sample: 13, Max Defectives: 0]
    B -->|151-300| D[Sample: 20, Max Defectives: 1]
    B -->|301-500| E[Sample: 32, Max Defectives: 2]
    B -->|501-100

IS 3818: Materials for Continuous (Piano) Hinges

Key Material Specifications (Table 1)

Notes:

• Material testing: Samples from each lot must be tested for conformity.
• Marking: Hinges may be marked with the Standard Mark per Clause 7.2.
• Tolerance & Dimensions: Refer to Figures 1-3 in IS 3818 for hinge dimensions and permissible tolerances.

Summary of Material Properties

flowchart LR
    A[Materials for Hinges] --> B[Flap]
    A --> C[Pin]
    B --> D[Mild Steel Sheet (IS 1079)]
    B --> E[Aluminium Alloy Sheet (IS 739)]
    B --> F[Cold Rolled Steel Sheet (IS 737, IS 513)]
    C --> G[Mild Steel Wire (IS 280)]
    C --> H[Aluminium Alloy Wire (IS 739)]

For detailed dimensions and tolerances, refer to IS 3818 Figures 1-3.

IS 3818: Dimensions and Tolerances for Continuous (Piano) Hinges

Key Points:

• All dimensions in millimetres (mm).
• Lengths other than standard can be supplied in multiples of 304 mm.
• Minimum screw hole distance from flap end:

Dimensions & Tolerances (Selected from Tables)

Additional Dimensions for Type IV Hinges (Counter-Sunk Holes)

| Nominal Size (mm) | B (±1 mm) | B1 (±1 mm) | B2 (±1 mm) | C (±1.5 mm) | Pin Dia, D (mm) | Thickness, T (

IS 3818: Manufacture of Continuous (Piano) Hinges – Key Specifications

1. Materials (Table 1)

2. Sampling & Quality Control (Clause 2.2, Table 2)

• Lot conformity: Lot is accepted if defectives ≤ permissible number.

3. Marking (Clause 7.2)

• Each hinge may be marked with the Standard Mark to indicate compliance.

4. Dimensions & Tolerances

• Refer to IS 3818 Figures 1, 2, and 3 for detailed hinge dimensions and tolerances.

flowchart TD
    A[Raw Material Selection] --> B[Manufacturing Process]
    B --> C[Sampling & Testing]
    C -->|Defectives ≤ Permissible| D[Lot Accepted]
    C -->|Defectives > Permissible| E[Lot Rejected]
    D --> F[Marking with BIS Standard Mark]

Summary: Use specified materials (Table 1), follow sampling plan (Table 2), ensure dimensional tolerances, and apply BIS mark for quality assurance.

IS 3818 - Finish Specifications for Continuous (Piano) Hinges

Key Points on Finish (Clause 6 & related):

• Hinges must be inspected for finish quality as per Clause 6.
• Finish should be smooth, free from defects like rust, burrs, or rough edges.
• Surface treatment (e.g., plating, painting) is applied as per purchaser's requirements or standard practice.
• Materials used (see Table 1) influence finish quality; e.g., mild steel, aluminium alloys, or cold-rolled steel require appropriate corrosion protection.
• Final product must comply with dimensional and manufacturing tolerances (Clause 4 & 5) to ensure finish integrity.

Material & Finish Relation (Table 1 Summary):

Dimensional Tolerances Affecting Finish (Clause 4):

• Precise dimensions ensure proper fit and surface contact, critical for finish durability.
• Tolerances per Fig. 1-3 ensure consistent hinge alignment, preventing finish damage during use.

Summary Table for Counter-Sunk Holes (Clause 28.6):

IS 3818 - Marking Key Points

1. Standard Marking (Clause 7.2)

• Each hinge may be marked with the BIS Standard Mark to assure compliance.
• Use of the Standard Mark follows BIS Act 1986 and ensures quality control and periodic conformity checks.

2. Material Specifications (Table 1)

3. Sampling & Quality Control (Clause 2.2, Table 2)

4. Countersunk Hole Dimensions (Clauses 9.5 & 28.6)

IS 3818: Packing Specifications for Hinges

Clause 8 (Packing):

• Hinges shall be packed in polyethylene sheet or other water-proof paper.
• Bundles of hinges: 5, 10, or multiples of 5 per bundle.
• Bundles are placed inside cardboard boxes lined with weather-proof paper.

Clause 8.2 (Labeling on Boxes):

Each box must have a label showing:

• Source of manufacture
• Type of hinge
• Size of hinge
• Quality of hinge

Key Dimensions & Notes (From Clause 1.5 and Table 7):

• Thickness of flap: 1.5 to 1.8 mm
• Bundle sizes: 5, 10, or multiples of 5 hinges
• Packing material: Polyethylene sheet or waterproof paper

Summary Table for Packing

Sampling & Conformity

• Refer Annex B for sampling methods and conformity criteria.

flowchart TD
    A[Hinges] --> B[Bundle in 5, 10, or multiples of 5]
    B --> C[Wrap in polyethylene sheet or waterproof paper]
    C --> D[Place bundles in cardboard box]
    D --> E[Line box with weather-proof paper]
    E --> F[Label box with manufacture details, type, size, quality]

This ensures protection from moisture and clear identification during storage and transport.

IS 3818: Sampling and Criteria for Conformity (Clause 9, Annex B)

Sampling Method:

• Samples drawn from each lot separately.
• At least 10% of packages (minimum 3) are selected.
• Equal number of hinges sampled from each selected package.

Criteria for Conformity:

• A lot conforms if the number of defective hinges ≤ permissible defectives (Table B-2).

Table: Scale of Sampling and Permissible Number of Defectives

Summary:

• Sampling ensures representative quality checks.
• Defective limits are strict to maintain quality.
• Use this table to decide sample size and acceptance criteria.

flowchart TD
    A[Start: Lot of Hinges] --> B[Select 10% packages (min 3)]
    B --> C[Draw equal samples from each package]
    C --> D[Count defective hinges]
    D --> E{Defectives ≤ Permissible?}
    E -- Yes --> F[Lot Accepted]
    E -- No --> G[Lot Rejected]

This ensures consistent quality control per IS 3818.

IS 3818 - Annex A: Relevant Indian Standards

Annex A lists Indian Standards essential for compliance with IS 3818 (Continuous/Piano Hinges). Key referenced IS codes include:

Important Notes:

• Materials for hinges must comply with these standards (e.g., Grade D steel as per IS 513:1986).
• Sampling and conformity criteria follow IS 4905:1968 (Annex B).
• Dimensions and tolerances conform to figures in IS 3818.
• Rounding off values per IS 2:1960.

Sampling Table (from IS 3818 Table 2)

flowchart LR
    A[IS 3818 Hinges] --> B[Material Standards]
    B --> IS280[Mild Steel Wire IS 280]
    B --> IS737[Aluminium Alloy IS 737]
    B --> IS1079[Steel Sheet IS 1079]
    A --> C[Sampling & Quality]
    C --> IS4905[Random Sampling IS 4905]
    C -->

IS 3818 - Annex B: Scale of Sampling and Criteria for Conformity

B-1 Scale of Sampling

• Samples are drawn from each lot separately to verify conformity.
• At least 10% of packages, minimum 3 packages, are selected.
• Equal number of hinges are taken from each selected package.

B-2 Number of Tests and Criteria for Conformity

• Lot conforms if defectives ≤ permissible number.
• Sampling ensures quality control per BIS norms.

Summary Diagram

flowchart TD
    A[Start: Lot of Hinges] --> B[Select 10% packages, min 3]
    B --> C[Draw equal samples from each package]
    C --> D[Total sample size per Table]
    D --> E{Count defectives}
    E -->|Defectives ≤ permissible| F[Lot Conforms]
    E -->|Defectives > permissible| G[Lot Rejected]

This method ensures reliable quality assurance for hinges under IS 3818.