Roller Chain Technical Snapshot

Each Roller Chain result row contains:

Section	Contents
class	DROP_IN_FIT, FIT_OR_BETTER, PENDING_VERIFICATION, and other non-recommendation values reserved for compatibility.
drop_in	True only for drop-in class.
scores	Final, dimension, feature, confidence, certainty, and band.
passed_gates	Gates that passed.
failed_gates	Gates that failed or need review.
differences.rows	Field-level comparison.
missing_info	Missing input/candidate fields.
evidence	Matched/conflicting/unverifiable fields and coverage.
highlights	User-facing explanation messages.
reason_codes	Machine-readable tags.
verification_status	MULTI_SOURCE_VERIFIED, SINGLE_SOURCE, or UNVERIFIED.
iso_dimension_mismatch	ISO dimension mismatch flag.
clearance_warning_flag	Clearance warning flag.
sprocket_warning_flag	Sprocket compatibility warning.
fb_comparison	Strength comparison: CONFIRMED_GTE, CANDIDATE_FB_UNKNOWN, REFERENCE_FB_UNKNOWN, FB_INSUFFICIENT.
fb_warning_flag	Strength warning flag.
fb_upgrade_contradiction	Upgrade contradiction flag.
fatigue_strength_class	ISO_VERIFIED, MFG_CLAIMED, or UNKNOWN.
decision_semantics	Geometry/performance basis for the decision.
pending_reason	Why a candidate is pending verification.
gate_report	Hard failures and conditional flags.