Logs for production of sliced veneers

IS 15457: Scope Summary

• Scope: Specifies requirements for logs used in production of sliced veneers.
• Referenced Standards:
  • IS 5248:1988 — Teak logs for sliced veneers
  • IS 6342:1987 — Rosewood logs for sliced veneers
  • IS 13240:1991 — Walnut logs for sliced veneers
• Rounding Off: Final test or analysis values must be rounded per IS 2:1960 rules, maintaining the same significant figures as specified.
• Definitions: As per IS 707 (Wood and Wood Products Terminology).

Key Points:

Rounding Off Rule (IS 2:1960):

• Round off numerical results to the same significant figures as the standard's specified value.

This standard integrates with related IS codes for detailed veneer log specifications and ensures uniformity in testing and reporting.

IS 15457 References Summary

• Referenced Standards for Veneer Logs:

• Rounding Off Rules:
  Follow IS 2:1960 for rounding numerical values.

  • Maintain the same number of significant digits as specified values.
  • Round final test or analysis results accordingly.

• Definitions:
  Use definitions as per IS 707 for terms related to veneers and logs.

Key Points:

• Always verify if newer editions of referenced IS codes are available.
• This standard incorporates provisions from the above IS codes by reference.

flowchart LR
    A[IS 15457 Standard] --> B[IS 5248:1988 - Teak Logs]
    A --> C[IS 6342:1987 - Rosewood Logs]
    A --> D[IS 13240:1991 - Walnut Logs]
    A --> E[IS 2:1960 - Rounding Rules]
    A --> F[IS 707 - Definitions]

This ensures consistency and clarity in veneer log specifications and testing.

IS 15457 - Definitions: Key Points

• Reference Standard: Definitions in IS 15457 are as per IS 707:1976 (Glossary of terms for timber technology and utilization).

• Rounding Off: Follow IS 2:1960 for rounding numerical values:

  • Round off to the same number of significant figures as the specified value.
  • Ensures consistency in test or analysis results.

• Cross-Referenced Standards: IS 15457 incorporates provisions from other standards by reference; users should verify the latest editions for compliance.

Summary Table

This ensures uniformity in terminology and numerical precision across timber-related standards.

IS 15457 - General Requirements Summary

1. Referenced Standards

   • This standard incorporates provisions from other IS codes valid at publication.
   • Users must check for the latest editions of referenced standards.

2. Rounding Off Rules

   • Follow IS 2:1960 for rounding numerical values.
   • The number of significant digits in the rounded value must match the specified value.

3. Definitions

   • Use definitions as per IS 707 for terms used in this standard.

Key Points

Rounding Off (as per IS 2:1960)

• If the digit following the last significant digit is <5, leave the last digit unchanged.
• If ≥5, increase the last digit by one.
• Example: 12.345 rounded to 3 significant digits = 12.3

If you need formulas or specific tables, please specify the clause or topic within IS 15457.

IS 15457: Permissible Defects and Deductions Summary

Key Specifications:

• Total defects limit:
  Maximum 2 defects per 2.5 m length of log (Clause 5.12).

• Defect restrictions:

  • Dote, Bird Peck, Wound, Fire Damage:
    • Max diameter: 12 mm
    • Max depth: 40 mm
    • Limited to one quadrant of the log circumference
    • Max 2 such defects per 2.5 m length (Clause 2.5)
  • Cracks or Checks:
    • Allowed if penetration ≤ 12 mm
    • If penetration > 12 mm, reduce girth by:
      [ \text{Girth reduction} = 6 \times \text{max penetration (mm)} ]
      (Clause 5.9)

• No plugging or covering of visible defects is allowed (Clause 4.3).

Defect Deduction Formula for Cracks:

Summary Table:

flowchart TD
    A[Log Length 2.5 m] --> B{Defects ≤ 2?}
    B -- Yes --> C[Check individual defects]
    B -- No --> D[Reject log or deduct]
    C --> E{Defect Type}
    E --> F[Dote/Bird Peck/Wound/Fire]
    E --> G[Cracks/Checks]
    F

IS 15457 - Grading and Measurement of Logs

Key Specifications:

• Defects Limit: Max 2 defects per 2.5 m length of log (Clause 5.12).
• Grading by Girth (Clause 6.1):
  • Grade I: Girth > 2000 mm
  • Grade II: 1500 mm < Girth ≤ 2000 mm
  • Grade III: 1000 mm < Girth ≤ 1500 mm

Measurement (Clause 6.2.3):

Volume ( V ) of a log is calculated by:

[ V = \frac{G^2}{4\pi} \times L ]

Where:

• ( V ) = volume in m³
• ( G ) = girth in meters
• ( L ) = length in meters

(Note: The formula assumes a circular cross-section where area ( A = \frac{G^2}{4\pi} ))

Marking on Logs (Clause 8):

• Supplier ID (initials)
• Length and mid-girth
• Grade symbol:
  • Square □ for Grade I
  • Triangle △ for Grade II
  • Circle ○ for Grade III

Inspection:

• Measurement and inspection must be done in presence of purchaser and supplier or as per contract (Clause 7).

flowchart LR
  A[Log] --> B[Measure Girth (G)]
  A --> C[Measure Length (L)]
  B & C --> D[Calculate Volume V = (G²/4π) × L]
  D --> E[Assign Grade based on Girth]
  E --> F[Mark Log Ends with ID, Size & Grade Symbol]

This summary ensures compliance with IS 15457 for grading, measurement, and marking of timber logs.

IS 15457: Measurement and Inspection - Key Points

• Rounding Off (Clause 6.2):
  Final test or analysis results must be rounded per IS 2:1960 rules, retaining the same number of significant digits as the specified value.

• Reference Standards:

  • IS 3364 (Part 1): Method for measurement and evaluation of timber defects, especially logs.
  • These referenced standards provide detailed measurement procedures and defect evaluation criteria.

Key Specifications for Measurement:

Summary:

• Use IS 2:1960 for rounding numerical results.
• Follow IS 3364 (Part 1) for timber measurement and defect evaluation.
• Always verify you use the latest editions of referenced standards.

flowchart TD
    A[Measurement/Inspection] --> B[Perform Test/Analysis]
    B --> C[Obtain Raw Result]
    C --> D[Round Off per IS 2:1960]
    D --> E[Compare with Specified Values]
    E --> F{Complies?}
    F -->|Yes| G[Accept]
    F -->|No| H[Reassess or Reject]

This ensures consistent, standardized evaluation per IS 15457.

IS 15457 - Prophylactic Treatment (Clause 8)

• Purpose: Protect logs from end cracking, splitting, fungal and insect attacks immediately after felling and cross-cutting.
• Standard Reference: Treatment shall follow IS 9104:1979 - Guide for storage and protection of logs and sawn timber.
• Marking of Logs: Each log must be marked on both ends with:
  • Supplier's ID (abbreviated initials)
  • Length (L) and mid-girth (G)
  • Grade identification:
    • Grade I: Square (■)
    • Grade II: Triangle (▲)
    • Grade III: Circle (●)

Volume Calculation (Clause 6.2.3)

[ V = \frac{G^2}{4\pi} \times L ]

• V: Volume in m³
• G: Girth (circumference) in meters
• L: Length in meters

Summary Diagram:

flowchart LR
    A[Felling & Cross-cutting] --> B[Prophylactic Treatment (IS 9104)]
    B --> C[Mark Logs]
    C --> D{Markings}
    D -->|Supplier ID| E[Initials]
    D -->|Length & Girth| F[L & G]
    D -->|Grade| G[■ / ▲ / ●]

Note: Refer to IS 9104 for specific treatment chemicals and methods.

IS 15457 - Marking of Logs: Key Points and Specifications

Marking Requirements (Clause 8 & 10.1)

• Each log must be marked legibly and indelibly on both ends with:
  • Supplier's ID (abbreviated initials)
  • Length (L) and Mid-girth (G) of the log
  • Grade identification symbol:
    • Grade I: Square □
    • Grade II: Triangle △
    • Grade III: Circle ○

Volume Calculation (Clause 6.2.3)

• Volume of a log (V) is calculated as:

  [ V = \text{volume in m}^3; \quad G = \text{girth in m}; \quad L = \text{length in m} ]

  (Exact formula not provided in excerpt, but typically volume for logs is approximated by formulas like Smalian’s or Huber’s formula using girth and length.)

BIS Standard Mark (Clause 10.2)

• Use of the BIS Standard Mark is governed by the Bureau of Indian Standards Act, 1986.
• License required for use; details available from BIS.
• Marking ensures traceability and compliance with quality.

Summary Table for Marking Symbols:

Additional Notes

• Measurement and inspection must be done in presence of purchaser and supplier representatives.
• Logs should be treated prophylactically as per IS 9104 to prevent damage.
• Numerical values must be rounded as per IS 2:1960 rules.

flowchart LR
    A[Log] --> B{Mark Both Ends}
    B --> C[Supplier's ID]
    B --> D[Length & Mid-girth]
    B --> E{Grade Symbol}
    E --> F[Grade I: □]
    E --> G[Grade II: △]
    E --> H[Grade III: ○]

For detailed licensing and marking rules, contact BIS regional offices or visit www.bis.org.in.

BIS Certification Marking (IS 15457 - Clause 10.2)

• Governing Act: Use of BIS Standard Mark is governed by the Bureau of Indian Standards Act, 1986 and related rules.
• License: Manufacturers must obtain a license from BIS to use the Standard Mark.
• Marking Details on Logs (Clause 8):
  • Supplier's ID (initials)
  • Length and mid-girth (in meters)
  • Grade identification by symbols:
    • Grade I: Square □
    • Grade II: Triangle △
    • Grade III: Circle ○
• Volume Calculation of Logs (Clause 6.2.3):

[ V = \frac{G^2}{4\pi} \times L ]

Where:

• (V) = volume (m³)

• (G) = girth (m)

• (L) = length (m)

• Rounding Off: Follow IS 2:1960 for numerical rounding to maintain significant figures.

Important Contacts for BIS Licensing

Summary

• BIS Marking certifies product conformity.
• License required for use.
• Logs must be marked with supplier ID, dimensions, and grade symbol.
• Volume formula and rounding rules ensure measurement accuracy.

flowchart LR
    A[Manufacturer] --> B[Apply for BIS License]
    B --> C[License Granted]
    C --> D[Use BIS Standard Mark]
    D --> E[Mark Logs with ID, Size, Grade]
    E --> F[Compliance & Inspection]

For detailed licensing conditions, contact BIS regional offices or visit www.bis.org.in.