Methods of Test for Clear Finishes for Wooden Furniture, Part VI: Resistance to Mechanical Damage

IS 5807 Part 6 (1978) – Scope & Key Specifications

• Scope: Specifies detailed dimensions and construction for scraper blades, scrape heads, and related accessories used in testing coatings.
• Dimensional Accuracy: All dimensions in millimeters with tolerance ±0.1 mm unless stated otherwise.

Key Specifications & Details

Notes

• Clauses 3.2 and 3.3 require purchaser-seller agreement on specifics.
• Observations on failure modes (e.g., adhesion issues) to be noted (Clause 4.4.3.5).

flowchart LR
    A[Scraper Blade Holder] --> B[Scraper Blade Projection (6-35 mm)]
    A --> C[Clamp & Clearance Hole for Screws]
    D[Scrape Head] --> E[Drill & Tap for Screw Drive]
    D --> F[Direction of Scrape]
    G[Cutting Blade] --> H[11 Slits, 1mm x 50mm, 2 ± 0.01 mm apart]
    I[Table] --> J[Horizontal & Height Adjustable]
    I --> K[Reference Bar Parallel to Support Arm]

This standard ensures precise dimensional control and setup for coating adhesion testing tools.

IS 5807 Part 6 (1978) - Key Specifications & Table

This part of IS 5807 deals with surface penetration force rating for materials or components.

Key Table: Force at Surface Penetration vs. Rating (Clause 4.4.4.2)

Notes:

• The basic rating is directly obtained from the force required to penetrate the surface.
• Clauses 3.2 and 3.3 emphasize that agreements between purchaser and seller are essential for specific conditions or interpretations.
• No explicit formulas are provided; the rating is purely based on measured force values.

This rating system helps quantify surface resistance or hardness based on penetration force, useful for quality control or material specification compliance.

IS 5807 Part 6: General Requirements - Key Specifications & Formulas

• Agreement Clause (3.2):
  Purchaser and seller must mutually agree on specific requirements not detailed in the standard.

• Basic Rating (Clause 4.4.4.2):
  The rating is based on the force (in Newtons) required to penetrate the surface. Use the table below to determine the rating:

• Interpretation:
  Higher force indicates better surface resistance or quality.

This table is essential for assessing surface penetration resistance in line with IS 5807 Part 6. Ensure purchaser-seller agreements cover any additional parameters.

IS 5807 Part 6: Test Procedure - Key Points

1. Apparatus (Clause 4.2.1)

• Use specified instruments for measuring surface roughness and texture.
• Ensure calibration and accuracy as per standard.

2. Procedure (Clauses 4.2.2 & 4.3.2)

• Follow a systematic method for each test component (e.g., roughness, texture, and other parameters).
• Take multiple readings at designated locations on the test surface.
• Average the readings to obtain representative values.

3. Method of Assessment (Clause 2.4)

• Perform three component tests on the surface.
• Obtain a rating for each test.
• Calculate the overall rating by combining individual ratings (e.g., average or weighted average).

4. Preparation of Test Surface (Clause 3)

• Clean and prepare surface to remove debris or irregularities.
• Ensure surface is representative of actual conditions.

Typical Formula for Overall Rating:

[ \text{Overall Rating} = \frac{R_1 + R_2 + R_3}{3} ]

Where:

• ( R_1, R_2, R_3 ) = Ratings from each component test.

Summary Table (Example)

flowchart TD
    A[Prepare Test Surface] --> B[Conduct Component Test 1]
    B --> C[Conduct Component Test 2]
    C --> D[Conduct Component Test 3]
    D --> E[Calculate Individual Ratings]
    E --> F[Compute Overall Rating]

This concise approach ensures compliance with IS 5807 Part 6 test procedures.

IS 5807 Part 6 (1978) – General Overview

This part of IS 5807 deals with specifications for steel wire ropes used in various engineering applications.

Key Points:

• Agreement Clause (3.2 & 3.3):
  Purchaser and seller must agree on specific requirements such as rope construction, diameter, breaking load, and tolerance.

• General Specifications:

  • Wire ropes are classified by construction type (e.g., 6x19, 6x36).
  • Diameter tolerance typically ±2% of nominal diameter.
  • Breaking load depends on wire rope construction and diameter.

Typical Formula for Breaking Load (Approximate):

[ \text{Breaking Load} = \text{Nominal Cross-Sectional Area} \times \text{Minimum Tensile Strength} ]

Where:

• Tensile strength of steel wire ropes ~ 1570 N/mm² (varies by grade)
• Cross-sectional area depends on rope diameter (d):

[ A = \frac{\pi}{4} d^2 ]

Example Table Extract (Indicative):

Summary:

• Purchaser-seller agreement is essential for specific parameters.
• Diameter and breaking load are primary specs.
• Use cross-sectional area and tensile strength for calculations.

flowchart LR
    A[Purchaser] -->|Specify requirements| B[Seller]
    B -->|Confirm specs| A
    A --> C{Agreement on}
    C --> D[Rope Construction]
    C --> E[Diameter]
    C --> F[Breaking Load]

For detailed tables and exact values, refer to the full IS 5807 Part 6 document.

IS 5807 Part 6 (1978) — Impact Test Summary

Test Description (Clause 2.1, 4.2)

• A standard steel ball is dropped from a specified height onto the test panel.
• Damage to the finish around the indentation is visually assessed.
• At least 5 observers rate the damage using a numerical rating code (see Clause 4.2.3).

Impact Rating (Clause 5.1.1)

• Each test area is rated by 5 observers.
• No intermediate ratings (e.g., 3-2) allowed.
• The final impact rating is the largest rating value equaled or exceeded by the majority.

Test Procedure (Clause 4.1)

• Conduct 3 separate tests: impact, cross-cut, and scrape.
• Each test at minimum 2 positions on different grain structures.
• Test temperature: 27 ± 2°C.

Notes:

• The height and ball size are standardized but not specified here; refer to IS 5807 Part 6 for exact values.
• Rounding rules for numerical values apply as per the revised guidelines.

flowchart LR
    A[Steel Ball Drop] --> B[Indentation on Panel]
    B --> C[Damage Assessment by 5 Observers]
    C --> D[Assign Numerical Ratings]
    D --> E[Determine Majority Rating]
    E --> F[Final Impact Rating]

This method ensures consistent, reproducible evaluation of coating impact resistance per IS 5807 Part 6.

IS 5807 Part 6: Cross-Cut Test Summary

Test Description (Clauses 2.2, 4.3.2.2)

• Lattice pattern: Two sets of 11 cuts each, at right angles.
• Cut spacing: 2 mm apart.
• Cut length: ~35 mm.
• Cut direction: Approximately 45° to the grain.
• Tool: Sharp blade in holder, edge facing movement.
• Post-cut: Remove loose finish with a soft brush.

Cross-Cut Rating (Clause 5.1.2)

• Rated by ≥5 observers.
• Use integer ratings only (no intermediate values).
• Final rating = largest rating met or exceeded by the majority.

Example Rating Calculation

Key Specifications Table

flowchart TD
    A[Start Test] --> B[Make lattice pattern]
    B --> C{2 sets of cuts}
    C -->|Set 1| D[11 cuts, 2 mm apart]
    C -->|Set 2| E[11 cuts, 2 mm apart at 90°]
    D --> F[Cut length 35 mm at 45° to grain]
    E --> F
    F --> G[Remove loose finish with soft brush]
    G --> H[Rating by ≥5 observers]
    H --> I[Determine majority rating]
    I --> J[Final Cross-Cut Rating]

This test assesses coating adhesion by evaluating how much finish detaches along the lattice cuts.

IS 5807 Part 6: Scrape Test Key Points

Test Description (Clauses 2.3 & 4.4)

• A standard scraper blade is drawn across the grain of the test surface at constant speed.
• Force is gradually increased until:
  • Surface penetration occurs.
  • Further force causes penetration to the substrate.
• Forces at these two points are recorded.

Measurement & Rating (Clauses 4.4.4.1 & 5.1.3)

• Scrape resistance = force at surface penetration.
• Additional force to penetrate the finish film reflects properties like toughness, brittleness, adhesion.
• A basic rating is calculated from surface penetration force.
• This rating is modified based on force to penetrate the film.
• At least five observers independently assess and rate the test.
• No marks should be left on panels to avoid bias.

Summary Table (Conceptual)

flowchart LR
    A[Start Scrape Test] --> B[Apply scraper blade across grain]
    B --> C[Increase force gradually]
    C --> D{Force reaches surface penetration?}
    D -- No --> C
    D -- Yes --> E[Record surface penetration force]
    E --> F{Force reaches substrate penetration?}
    F -- No --> G[Calculate basic rating]
    F -- Yes --> H[Record substrate penetration force]
    H --> I[Modify rating based on substrate force]
    G --> J[Observers assess rating]
    I --> J

This test quantifies finish durability by measuring forces at critical penetration points, ensuring reliable coating performance evaluation.

IS 5807 Part 6: Assessment and Reporting of Results

Key Formulas and Specifications

1. Modified Rating Factor (Clause 4.4.4.3)

[ \text{Modifying Factor} = \frac{\text{Force at penetration to substrate (N)} - \text{Force at surface penetration (N)}}{\text{Force at surface penetration (N)}} ]

• Round to 1 decimal place
• Limit max value = 4
• Modified Rating = Basic Rating + Modifying Factor

2. Assessment Method (Clause 2.4)

• Obtain ratings for each of the 3 component tests
• Calculate an overall assessment by combining these ratings.

3. Reporting of Results (Clause 5.2)

• Report:
  • Individual component test ratings
  • Modified rating (if applicable)
  • Overall assessment
  • Test conditions and surface preparation details (Clause 3)

Summary Table for Modified Rating

flowchart TD
    A[Perform 3 Component Tests] --> B[Calculate Basic Ratings]
    B --> C[Measure Forces at Surface & Substrate]
    C --> D[Calculate Modifying Factor]
    D --> E[Add to Basic Rating → Modified Rating]
    E --> F[Combine Ratings → Overall Assessment]
    F --> G[Prepare Report with Details]

This ensures consistent assessment and transparent reporting as per IS 5807 Part 6.

IS 5807 Part 6: Determination of Ratings

Key Formulas and Tables

1. Basic Rating (Clause 4.4.4.2)

Based on Force at Surface Penetration (N):

2. Modified Rating (Clause 4.4.4.3)

Calculate the Modifying Factor (MF) as:

[ MF = \frac{F_{\text{penetration to substrate}} - F_{\text{surface penetration}}}{F_{\text{surface penetration}}} ]

• Round MF to 1 decimal place
• Limit MF to a maximum of 4
• Then,

[ \text{Modified Rating} = \text{Basic Rating} + MF ]

Reporting Requirements (Clause 5.2.1)

• Average impact rating and abnormalities
• Average cross-cut rating and abnormalities
• Average scrape rating, average forces at surface penetration and substrate penetration
• Overall rating

flowchart TD
    A[Measure Force at Surface Penetration] --> B[Determine Basic Rating from Table]
    B --> C[Measure Force at Penetration to Substrate]
    C --> D[Calculate Modifying Factor (MF)]
    D --> E[Limit MF to max 4]
    E --> F[Add MF to Basic Rating]
    F --> G[Report Modified Rating]

This method ensures a standardized and quantifiable assessment of coating adhesion or related surface properties per IS 5807 Part 6.

IS 5807 Part 6 (1978) — Reporting of Results

Key Formulas

• Modified Rating Factor (Clause 4.4.4.3):

[ \text{Modifying Factor} = \frac{\text{Force at penetration to substrate (N)} - \text{Force at surface penetration (N)}}{\text{Force at surface penetration (N)}} ]

• Limits:

  • Round to 1 decimal place
  • Maximum value = 4 (any value >4 is capped at 4)

• Modified Rating:

[ \text{Modified Rating} = \text{Basic Rating} + \text{Modifying Factor} ]

Reporting Requirements (Clause 5.2.1)

Report the following clearly:

• a) Average impact rating for all test areas + note abnormalities
• b) Average cross-cut rating for all test areas + abnormalities
• c) Average scrape rating, including:
  • Average force at surface penetration (N)
  • Average force at penetration to substrate (N)
• d) Overall rating (summary of above)

Summary Table for Reporting

flowchart TD
    A[Measure Forces] --> B[Calculate Modifying Factor]
    B --> C[Limit Factor to max 4]
    C --> D[Add to Basic Rating]
    D --> E[Report Modified Rating]
    E --> F[Compile Average Ratings]
    F --> G[Prepare Final Report]

This ensures standardized, clear, and comparable reporting of test results per IS 5807 Part 6.

IS 5807 Part 6: Acceptance Criteria Key Formulas and Tables

1. Basic Rating (Clause 4.4.4.2)

2. Appearance Rating of Test Area (Clause 4.2.3)

Note: Only finish damage is considered, not substrate deformation.

3. Modified Rating Formula (Clause 4.4.4.3)

[ \text{Modifying Factor} = \frac{\text{Force at penetration to substrate} - \text{Force at surface penetration}}{\text{Force at surface penetration}} ]

• Limit modifying factor to 4.0 max.
• Modified Rating = Basic Rating + Modifying Factor

Summary Flow

flowchart TD
    A[Measure Force at Surface Penetration] --> B{Determine Basic Rating}
    B --> C[Assign Rating 0 to 4]
    A --> D[Measure Force at Penetration to Substrate]
    D --> E[Calculate Modifying Factor]
    E --> F[Limit to max 4]
    C --> G[Add Modifying Factor]
    F --> G
    G --> H[Obtain Modified Rating]

Note: Final acceptance depends on purchaser-seller agreement (Clause 3.2).